to keep stock bottles from contamination, what should never be placed inside of them? select all which apply.

Answers

Answer 1

To keep stock bottles from contamination, certain precautions must be taken to ensure the purity of the contents, all the options (a), (b), (c) and (d) can be applied.

Firstly, unused chemicals should never be placed inside of stock bottles. Secondly, personal droppers should not be used, as they may introduce impurities into the bottle. Thirdly, hands should not be placed inside of the bottle, as they may introduce bacteria or other contaminants. Lastly, personal spatulas should not be used, as they may contain traces of other chemicals or contaminants that can affect the purity of the contents.

In order to maintain the purity of the contents of stock bottles, it is recommended to use dedicated and properly labeled equipment, and to avoid contact with anything that may introduce impurities or contaminants.

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Complete question :

To keep stock bottles from contamination, what should never be placed inside of them? Select all which apply.

A) unused chemicals

B) your personal droppers

C) your hands

D) your personal spatulas


Related Questions

When there is a bulky group on a cyclohexane and it flips what happens to the overall structure and what position is the t-butyl group?(reduction lab)

Answers

Chair flipping of cyclohexane with bulky t-butyl group leads to interconversion of axial and equatorial positions, causing a change in overall conformation.

What happens to the overall structure and position of t-butyl group during chair flipping of a cyclohexane?

When a bulky group such as t-butyl (tert-butyl) is present on a cyclohexane ring, it can cause steric hindrance in its axial position. As a result, the molecule undergoes a process called chair flipping, where the axial and equatorial positions of the substituents on the cyclohexane ring interchange.

During the chair flip, the t-butyl group moves from the axial position to the equatorial position or vice versa, depending on whether it was originally in the up or down position. This interconversion between the axial and equatorial positions of substituents leads to a change in the overall conformation of the molecule, causing it to adopt a different chair conformation.

In summary, when a bulky group like t-butyl is present on a cyclohexane ring, it undergoes chair flipping to reduce steric hindrance. During this process, the t-butyl group changes position from axial to equatorial or vice versa, leading to a change in the overall conformation of the molecule.

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Consider these two entries from a fictional table of standard reduction potentials.

X2+ + 2e- => X(s) E=1.85 V
Y2+ + 2e- => Y(s) E=0.39 V

Which pair of species would react under standard conditions?

_X and Y2+
_X2+ and Y
_X2+ and Y2+
_X and Y

Answers

_X2+ and Y2+

Under standard conditions, the species with the higher reduction potential (X2+) will act as the oxidizing agent (gain electrons) while the species with the lower reduction potential (Y2+) will act as the reducing agent (lose electrons). This will result in a spontaneous redox reaction between X2+ and Y2+.

Under standard conditions, the direction of electron flow in a redox reaction is determined by the difference in reduction potentials between the two species involved.

The species with the higher reduction potential will have a greater tendency to gain electrons, while the species with the lower reduction potential will have a greater tendency to lose electrons.

In this case, since X2+ has the higher reduction potential, it will attract electrons from Y2+ and oxidize it. This will result in a spontaneous redox reaction between X2+ and Y2+.

The specific reaction and products will depend on the identity of X and Y, as well as the reaction conditions such as temperature, pressure, and concentration.

In summary, the species with the higher reduction potential acts as the oxidizing agent, while the species with the lower reduction potential acts as the reducing agent in a redox reaction.

The direction of electron flow is determined by the difference in reduction potentials, and the resulting reaction is spontaneous under standard conditions.

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What is the empirical formula of a substance that is 53. 5% c, 15. 5% h, and 31. 1% n by weight?.

Answers

The empirical formula of a substance that is 53.5% C, 15.5% H, and 31.1% N by weight is C₂H₅N.

To find the empirical formula, follow these steps:
1. Assume you have 100g of the substance, which makes the given percentages equivalent to grams (53.5g C, 15.5g H, 31.1g N).
2. Convert grams to moles for each element:
  - C: 53.5g / 12.01g/mol ≈ 4.46 mol
  - H: 15.5g / 1.01g/mol ≈ 15.35 mol
  - N: 31.1g / 14.01g/mol ≈ 2.22 mol
3. Divide all mole values by the smallest mole value to find the mole ratio:
  - C: 4.46 / 2.22 ≈ 2
  - H: 15.35 / 2.22 ≈ 7
  - N: 2.22 / 2.22 ≈ 1
4. Due to rounding errors, adjust the H ratio to the nearest whole number (5 in this case).
5. The empirical formula is therefore C₂H₅N.

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How to tell if a smoke detector detects carbon monoxide?.

Answers

Smoke detector does not specifically mention carbon monoxide detection, it likely does not have this feature. In that case, it's important to install a separate carbon monoxide detector in your home to ensure proper protection against this dangerous gas.

To determine if a smoke detector detects carbon monoxide, please follow these steps:

1. Check the packaging or label: Look for any mention of "carbon monoxide detection," "CO detection," or a similar phrase. This indicates that the device is designed to detect carbon monoxide.

2. Examine the device itself: Look for any symbols or labels indicating carbon monoxide detection. These may include a "CO" symbol or text indicating the presence of a carbon monoxide sensor.

3. Refer to the user manual: Consult the user manual or product documentation for information on the smoke detector's features and capabilities. Look for any mention of carbon monoxide detection.

4. Identify the type of smoke detector: There are two main types of smoke detectors: ionization and photoelectric. Ionization detectors are generally not designed to detect carbon monoxide, while photoelectric detectors may include a CO detection feature. Combination smoke/CO detectors will have both types of sensors.

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Carry out the following calculation and express the answer with the appropriate number of significant figures: (2.4056 x 1.4002) + 0.0953 Do not enter units or spaces in your response. Carry out the following calculation and express the answer with the appropriate number of significant figures:
(3.292 x 0.0045) – 2.8951 Do not enter units or spaces in your response.

Answers

The answers for the calculations are 3.4633 and -2.880, both expressed with the appropriate number of significant figures.



For the first calculation: (2.4056 x 1.4002) + 0.0953 = 3.36800872 + 0.0953
Since the least number of significant figures in the given numbers is 4, the answer should have 4 significant figures: 3.368 + 0.0953 = 3.4633.
For the second calculation: (3.292 x 0.0045) - 2.8951 = 0.014814 - 2.8951
Since the least number of significant figures in the given numbers is 3, the answer should have 3 significant figures: 0.0148 - 2.895 = -2.880.
In each calculation, we perform the operations and consider the least number of significant figures in the given numbers to determine the appropriate number of significant figures in the final answer.


Summary:
The answers for the calculations are 3.4633 and -2.880, both expressed with the appropriate number of significant figures.

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Which is a Brønsted - Lowry conjugate acid/ base pair?H3O+/OH-OH-/O2-H2SO4/SO4 2-NH4 +/NH2 -

Answers

Out of the given options, the Brønsted-Lowry conjugate acid-base pairs are:

H3O+/H2O (conjugate acid: H3O+; conjugate base: H2O)OH-/H2O (conjugate acid: H2O; conjugate base: OH-)H2SO4/HSO4- (conjugate acid: H2SO4; conjugate base: HSO4-)NH4+/NH3 (conjugate acid: NH4+; conjugate base: NH3)

Therefore, the correct answer is NH4+/NH3.

The Brønsted-Lowry conjugate acid-base pairs are related by the transfer of a single proton. In the Brønsted-Lowry acid-base theory, an acid is defined as a substance that donates a proton (H+) and a base is defined as a substance that accepts a proton. A conjugate acid-base pair is a pair of two molecules or ions that differ by the loss or gain of a single proton.

In an acid-base reaction, the acid donates a proton to the base, forming a conjugate acid and a conjugate base. The conjugate base is the remaining species after the acid has donated its proton, and it is able to act as a base itself by accepting a proton in a subsequent reaction. The conjugate acid is the species that is formed when the base accepts the proton, and it is able to act as an acid itself by donating a proton in a subsequent reaction.

For example, consider the reaction between hydrochloric acid (HCl) and water (H2O):

HCl + H2O → H3O+ + Cl-

In this reaction, HCl donates a proton to water, which accepts the proton to form hydronium ion (H3O+) as the conjugate acid and chloride ion (Cl-) as the conjugate base. The reverse reaction, in which H3O+ donates a proton to Cl-, would form HCl and H2O, completing the conjugate acid-base pair.

Similarly, consider the reaction between ammonia (NH3) and water:

NH3 + H2O → NH4+ + OH-

In this reaction, NH3 accepts a proton from water to form ammonium ion (NH4+) as the conjugate acid and hydroxide ion (OH-) as the conjugate base. The reverse reaction, in which NH4+ donates a proton to OH-, would form NH3 and H2O, completing the conjugate acid-base pair.

In summary, a conjugate acid-base pair is formed by two species that differ by the gain or loss of a single proton. In an acid-base reaction, the acid donates a proton to the base, forming a conjugate acid and conjugate base. The reverse reaction, in which the conjugate acid donates a proton to the conjugate base, forms the original acid and base, completing the conjugate acid-base pair.

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*NF3 is nearly nonpolar while NH3 is very polar; How does this support the fact that both undergo sp3 hybridization?

Answers

The more polar the connection is the larger the difference in electronegativity between the two atoms. N-F < N-H is the electronegative difference.

Define polarity

A molecule or its chemical groups that have polarity have an electric dipole moment with a negatively charged end and a positively charged end. Polarity is the separation of electric charge. Because the connected atoms' electronegativity differs, polar compounds must have at least one polar bond.

NH3 and NF3 are both trigonal pyramidal (TBSP) structures. Three polar bonds connect both molecules. There is a net dipole moment because the dipole moments connected to the polar bonds do not completely cancel one another out. Since both are polar, the more polar the connection is the larger the difference in electronegativity between the two atoms. N-F < N-H is the electronegative difference.

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You will observe a weak acid-strong base titration in this experiment. Select all statements that are true about weak acid-strong base titrations.

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In a weak acid-strong base titration, a weak acid is gradually neutralized by a strong base. This reaction involves the transfer of protons from the acid to the base until the equivalence point is reached.
The equivalence point of a weak acid-strong base titration occurs when the moles of acid are equal to the moles of base. At this point, the pH of the solution is typically greater than 7, indicating a basic solution. A weak acid-strong base titration can be used to determine the concentration of the acid. This is done by measuring the amount of base required to neutralize the acid and reach the equivalence point.

The pH of a weak acid-strong base titration initially decreases as the strong base is added, but as the equivalence point is reached, the pH increases rapidly overall, weak acid-strong base titrations can be used to determine the concentration of weak acids and provide valuable information about the chemical properties of these substances.

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determine the theoretical yield of h2s (in moles) if 32 mol al2s3 and 32 mol h2o are reacted according to the following balanced reaction. a possibly useful molar mass is al2s3

Answers

The theoretical yield of H₂S is 16 mol. To determine the theoretical yield of H₂S (in moles) in this reaction, we first need to write out the balanced chemical equation: Al₂S₃ + 6 H₂O → 2Al(OH)₃ + 3H₂S

From the equation, we can see that for every 1 mol of Al₂S₃ and 6 mol of  H₂O reacted, we will produce 3 mol of H₂S. Therefore, we need to determine which reactant will limit the amount of H₂S that can be produced, as this will be the maximum amount of H₂S that we can obtain.

To do this, we need to calculate the number of moles of  H₂O and Al₂S₃ that we have:

Number of moles of  H₂O = 32 mol
Number of moles of Al₂S₃ = 32 mol

Next, we need to determine which reactant is limiting by calculating the number of moles of H₂S that would be produced if all of the Al₂S₃ reacted:

Number of moles of H₂S produced = (32 mol Al₂S₃) × (3 mol H₂S / 1 mol Al₂S₃) = 96 mol H₂S

However, we also need to check if we have enough H₂O to react with all of the Al₂S₃. To do this, we calculate the number of moles of H₂S that would be produced if all of the H₂O reacted:

Number of moles of H₂S produced = (32 mol H₂O) × (3 mol H₂S / 6 mol H₂O) = 16 mol H₂S

Since we have less H₂S produced when all of the  H₂O reacts, this means that the  H₂O is the limiting reactant. Therefore, the theoretical yield of H₂S is 16 mol.

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List some important notes about fractional distillation...

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Here are some important notes about fractional distillation:

1. Fractional distillation is a process used to separate a mixture of liquids based on their boiling points.

2. The process involves heating the mixture to vaporize it, and then condensing the vapors back into liquid form.

3. As the temperature of the mixture increases, the liquids with lower boiling points will vaporize first, and can be collected separately.

4. A fractionating column is used in the process to separate the different components of the mixture by their boiling points.

5. The fractionating column is packed with materials such as glass beads, which provide a large surface area for the vapors to condense and re-vaporize.

6. As the vapors rise through the fractionating column, they are repeatedly condensed and re-vaporized, with the components with higher boiling points condensing and falling back down the column, while the components with lower boiling points continue to rise and be collected separately.

7. The temperature of the mixture is carefully controlled throughout the process to ensure that the components are separated efficiently.

8. Fractional distillation is commonly used in the petroleum industry to separate crude oil into its various components, such as gasoline, diesel fuel, and kerosene.

9. It is also used in the production of alcoholic beverages, such as whiskey and rum, to separate and concentrate the alcohol content.

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Why does the graph of atomic size have peaks at the alkali metals and valleys at the noble gases, rather than just increasing along a straight line according to atomic number?.

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The graph of atomic size, also known as atomic radius, shows the size of the atoms of the elements as a function of their atomic number.

While it is true that the atomic radius generally increases as we move down a group and from right to left across a period in the periodic table, there are some notable deviations from this trend that result in peaks and valleys in the graph.One of the main factors that contributes to the observed peaks and valleys is the effect of the electron configuration on the size of the atom. In the case of the alkali metals, for example, each successive element in the group has an additional electron shell, which results in a significant increase in atomic size. This is because the additional electron shell increases the average distance between the outermost electrons and the nucleus, thereby increasing the size of the atom.

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a 19.24 ml volume of 0.175 m kmno4 solution is needed to oxidize 28 ml of a feso4 solution in an acidic medium. what is the concentration of the feso4 solution in molarity? the net ionic equation is: see last slide chapter 4 power point. 5fe2 mno4- 8h ------> mn2 5fe3 4h2o

Answers

To find the concentration of the feso4 solution in molarity, we need to use the balanced net ionic equation and the given information about the kmno4 solution. The balanced equation shows that 5 moles of Fe2+ are oxidized by 1 mole of kmno4. Therefore, we can calculate the number of moles of kmno4 used in the reaction:

0.175 mol/L x 0.01924 L = 0.00337 moles of kmno4

Since 5 moles of Fe2+ are oxidized by 1 mole of kmno4, we can calculate the number of moles of Fe2+ in the 28 mL solution:

Molarity = moles of solute/volume of solution in liters

Molarity of FeSO4 = (5/1) x (0.00337 moles kmno4/0.028 L) = 0.603 M

Therefore, the concentration of the feso4 solution in molarity is 0.603 M.
To find the concentration of the FeSO4 solution in molarity, we can use the concept of stoichiometry and the balanced net ionic equation provided:

5Fe²⁺ + MnO₄⁻ + 8H⁺ → Mn²⁺ + 5Fe³⁺ + 4H₂O

First, determine the moles of KMnO4 used:
moles of KMnO4 = (volume of KMnO4) x (molarity of KMnO4) = 0.01924 L x 0.175 M = 0.003366 moles

Using the stoichiometric ratio from the balanced equation, we can determine the moles of FeSO4:
moles of FeSO4 = (moles of KMnO4) x (5 moles of Fe²⁺ / 1 mole of MnO₄⁻) = 0.003366 moles x 5 = 0.01683 moles

Finally, we can calculate the concentration (molarity) of the FeSO4 solution:
Molarity of FeSO4 = moles of FeSO4 / volume of FeSO4 solution = 0.01683 moles / 0.028 L = 0.6011 M

The concentration of the FeSO4 solution in molarity is 0.6011 M.

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I have 345 ml of a 1. 5 m nacl solution. If i boil the water until the volume of the solution is 250 ml, what will the molarity of the solution be?.

Answers

After boiling the water, the molarity of the NaCl solution will be approximately 2.07 M.


To find the new molarity of the solution, we need to use the equation M1V1 = M2V2, where M1 is the initial molarity, V1 is the initial volume, M2 is the final molarity, and V2 is the final volume.
Given that the initial volume is 345 ml and the final volume is 250 ml, we can find V1 as follows:
M1V1 = M2V2
1.5 M x 345 ml = M2 x 250 ml
M2 = (1.5 M x 345 ml) / 250 ml
M2 = 2.07 M
Therefore, the molarity of the solution after boiling will be 2.07 M. This means that the concentration of NaCl in the solution has increased due to the removal of water through boiling.

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The noble gas thought to be significantly carcinogenic due to its radioactive decay and that of its decay products is:.

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The noble gas that is significantly carcinogenic due to its radioactive decay and that of its decay products is radon. Radon is a colorless and odorless gas that is formed naturally from the decay of uranium in rocks and soil.

Long-term exposure to high levels of radon can increase the risk of lung cancer, particularly in smokers. It is important to test homes and buildings for radon levels and take measures to reduce them if necessary.

The noble gas thought to be significantly carcinogenic due to its radioactive decay and that of its decay products is Radon. Radon is a noble gas that can be found in soil, rock, and groundwater. It is formed through the radioactive decay of uranium and thorium, and its own decay products can also be radioactive, increasing the risk of cancer when inhaled or ingested in high concentrations.

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which of the following is detected by the methyl red (mr) test? multiple choice lactic acid acetoin 2,3 butanediol low ph

Answers

Low pH is detected by the methyl red (MR) test. The MR test is a commonly used microbiological test to determine the ability of an organism to produce and maintain stable acid end-products from glucose fermentation. Option D.

The test is performed by adding a pH indicator called methyl red to the test tube containing the bacterial culture and observing the color change of the solution. If the pH is low (acidic), the methyl red indicator turns red, indicating a positive test. On the other hand, if the pH is higher (less acidic), the methyl red indicator turns yellow, indicating a negative test. Therefore, the MR test is used to distinguish between mixed acid fermenters (positive MR test) and non-mixed acid fermenters (negative MR test) based on their ability to produce acidic end-products.

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Full Question

which of the following is detected by the methyl red (mr) test? multiple choice

lactic

acid acetoin

2,3 butanediol

low ph

every atom and molecule has its own unique color fingerprint as revealed by spectral lines. group of answer choices true false

Answers

This statement is true that every atom and molecule has its own unique color fingerprint as revealed by spectral lines.

Every atom and molecule has a unique set of energy levels, which correspond to specific wavelengths of light that they can absorb or emit. When an atom or molecule absorbs or emits light, it does so at these specific wavelengths, creating a unique spectral fingerprint that can be used to identify the substance. This is why scientists use spectral analysis techniques to identify the composition of unknown substances.

The spectral fingerprint of an atom or molecule is determined by the unique arrangement of electrons and their energy levels within the atom or molecule. These energy levels are determined by the specific properties of the atoms or molecules, such as their atomic number, electronic structure, and molecular geometry. As a result, every atom and molecule has a unique set of energy levels and therefore a unique spectral fingerprint.

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Draw the full structural formulas of 1,2-dichloropropane

Answers

1,2-dichloropropane is a colorless liquid with a sweet odor. It is a type of chlorinated hydrocarbon that is used as a solvent, as well as in the production of plastics, adhesives, and other chemicals. It is also used as a fumigant for soil and grain, and as a component of some automotive and aviation fuels.

Exposure to 1,2-dichloropropane can be harmful to human health, particularly if it occurs through inhalation or skin contact. It is classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC), and prolonged exposure has been linked to liver and lung damage. The use of 1,2-dichloropropane is regulated in many countries to limit human exposure and protect the environment.

Here is the full structural formula for 1,2-dichloropropane:

   Cl       Cl

    |        |

H3C--CH--CH2

    |  

    H

In this structure, the two chlorine atoms (Cl) are attached to the first and second carbons of a three-carbon chain. The third carbon is attached to a methyl group (H3C) and a hydrogen atom (H). The molecule is called 1,2-dichloropropane because the two chlorine atoms are attached to adjacent carbons in the chain.

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rp-1 is highly refined form of kerosene used for many first stage rocket engines. the average composition of it is indicated by ch 1. 9 a. what is the stoichiometric mixture ratio (mr) for rp-1 and oxygen?

Answers

The stoichiometric mixture ratio for RP-1 and oxygen is 23:1.

The stoichiometric mixture ratio (MR) for RP-1 and oxygen can be calculated using the chemical formula of RP-1, which is C₁₅H₃₂, and the balanced chemical equation for the combustion of RP-1 with oxygen to form carbon dioxide and water vapor.

The balanced chemical equation for the combustion of RP-1 is:

C₁₅H₃₂ + 23O₂ → 15CO₂ + 16H₂O

From the equation, it can be seen that the stoichiometric ratio of oxygen to RP-1 is 23:1. As a result, the stoichiometric mixture ratio between RP-1 and oxygen is 23:1.

This means that for complete combustion of RP-1, 23 moles of oxygen are required for every 1 mole of RP-1. Any fuel-rich mixture with an MR less than 23:1 will result in unburned fuel, while any oxidizer-rich mixture with an MR greater than 23:1 will result in unreacted oxidizer.


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The molecular shape of a species, which is the arrangement of the bonded atoms around the central atom, is determined not only by the number of ______ electron domains that join the atoms, but by the number of _______ electron domains as well

Answers

The molecular shape of a species, which is the arrangement of the bonded atoms around the central atom, is determined not only by the number of bonding electron domains that join the atoms, but by the number of nonbonding electron domains as well.

Nonbonding electron domains, also known as lone pairs, can have a significant influence on the shape of a molecule because they take up more space than bonding electron domains. As a result, they can cause the bonded atoms to be pushed closer together, leading to a distorted molecular shape. Therefore, both bonding and nonbonding electron domains must be taken into account when determining the molecular shape of a species.

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how many milliliters of 0.090 m naoh are required to titrated 50.0 ml of 0.090 m benzoic acid (hc7h5o2) to the equivalence point? use 3 significant figures for your answer.

Answers

50 mL of 0.090 M NaOH is required to titrate 50.0 mL of 0.090 M benzoic acid to the equivalence point.

We need to use the balanced chemical equation for reaction:

[tex]HC_7H_5O_2 + NaOH\ - > NaC_7H_5O_2 + H_2O[/tex]

From the equation, we can see that the molar ratio of benzoic acid to NaOH is 1:1.

Therefore, the number of moles of NaOH required to reach the equivalence point is equal to the number of moles of benzoic acid:

moles of NaOH = moles of benzoic acid = [tex](0.090 M)(0.050 L)[/tex]

= 0.0045 moles

To calculate the volume of 0.090 M NaOH needed to reach the equivalence point, we can use the molarity and moles of NaOH:

The volume of NaOH = moles of NaOH / molarity of NaOH

The volume of NaOH = [tex]0.0045 moles / 0.090 M = 0.050 L[/tex]

(50 mL).

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Which variety of gemstone is formed from natural volcanic glass?.

Answers

obsidian

sorry i dont have an explanation but obsidian is known as a black glass like structure formed by lava

The variety of gemstone that is formed from natural volcanic glass is called "obsidian." Obsidian is a naturally occurring volcanic glass that forms when molten lava cools rapidly and does not have enough time to crystallize. It has a smooth, glassy texture and can come in various colors, including black, brown, gray, and even iridescent hues. While obsidian is not a traditional crystalline mineral like many other gemstones, it is still considered a valuable and attractive material for use in jewelry and decorative objects due to its unique appearance.

need to know the answer to this question

Answers

Answer: B

Explanation: I took test

If another 0.150 moles of H2 was added in a movable chamber filled up with H2, the volume of H2 increased from 3.30 L to 7.20 L. How many moles of 13.0 L H2 is? Assume temperature and pressure stayed constant.

Answers

The number of moles of H2 in the 13.0 L container is 0.858 moles.

Initially, the H2 was in a movable chamber of volume 3.30 L, and there were n1 moles of H2. Then, 0.150 moles of H2 were added to the chamber, increasing the volume to 7.20 L. Let n2 be the total number of moles of H2 in the chamber after the addition. Since the temperature and pressure stayed constant, we can use the combined gas law to solve for n2:

(P1 x V1) / n1 = (P2 x V2) / n2

where P1 and P2 are the initial and final pressures, V1 and V2 are the initial and final volumes, and n1 and n2 are the initial and final number of moles of H2.

Since the pressure is constant, we can simplify the equation to:

V1 / n1 = V2 / n2

Plugging in the values, we get:

3.30 L / n1 = 7.20 L / (n1 + 0.150 mol)

Solving for n1, we get:

n1 = 0.708 mol

This is the number of moles of H2 in the initial volume of 3.30 L. To find the number of moles in a 13.0 L container, we can use the following equation:

n1 / V1 = n2 / V2

where V1 is the initial volume (3.30 L) and V2 is the final volume (13.0 L).

Plugging in the values, we get:

0.708 mol / 3.30 L = n2 / 13.0 L

Solving for n2, we get:

n2 = 0.858 mol

Therefore, the number of moles of H2 in the 13.0 L container is 0.858 moles.

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Why do compounds of metals and nonmetals consist of ions.

Answers

Compounds of metals and nonmetals consist of ions because of the difference in electronegativity between the two types of elements.

Metals tend to have a low electronegativity, which means they have a tendency to lose electrons and form positive ions, also known as cations. Nonmetals, on the other hand, tend to have a high electronegativity, which means they have a tendency to gain electrons and form negative ions, also known as anions.

When a metal and nonmetal combine in a compound, the metal loses electrons to the nonmetal, forming cations and anions, which then attract each other due to their opposite charges and form an ionic bond.

This results in the compound consisting of ions. In summary, the difference in electronegativity between metals and nonmetals is the reason why compounds of metals and nonmetals consist of ions.

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The heat of vaporization AH of methanol (CH,OH) is 35.3 kJ/mol. Calculate the change in entropy AS when 2.0 g of methanol boils at 65.0 °C. Be sure your answer contains a unit symbol and the correct number of significant digits.

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The change in entropy ΔS for methanol when it boils can be calculated from the change in enthalpy and temperature.

To calculate the change in entropy (ΔS) when methanol boils, we need to use the equation:

ΔS = ΔH / T

First, we have to calculate the number of moles of methanol, using the molar mass of CH₃OH as 32.04 g/mol:

moles of CH₃OH = mass of CH₃OH ÷ molar mass of CH₃OH

= 2.0 g ÷ 32.04 g/mol = 0.062 mol

Temperature in Kelvin (T) = 65.0 °C + 273.15 = 338.15 K

Now we can calculate the change in entropy:

ΔS = ΔH ÷ T

= 35.3 kJ/mol ÷ (0.062 mol × 338.15 K)

= 1.640 kJ/(mol·K)

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when a stable diatomic molecule spontaneously forms from its atoms at constant pressure and temperatureT/F

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When a stable diatomic molecule spontaneously forms from its atoms at constant pressure and temperature, the statement is true.

When two atoms form a diatomic molecule, a chemical bond is created, and energy is released. This energy is typically in the form of heat or light, and the process is exothermic. Since the diatomic molecule has lower free energy than the individual atoms, the change in Gibbs free energy (ΔG) is negative, and the reaction occurs spontaneously at constant pressure and temperature.

Therefore, the answer is true.

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as indicated by lewis structures, which of the following would probably not exist as a stable molecule? question 10 options: 1) ch3oh 2) ch2o 3) ch3o 4) c2h2 5) c3h4

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CH3O (option 3) would probably not exist as a stable molecule according to Lewis structures.

According to Lewis structures, a stable molecule should have a complete octet of electrons in its valence shell. Therefore, the molecule that probably would not exist as a stable molecule is the one that cannot form a complete octet.

Option 4, C2H2 (acetylene), is the molecule that would probably not exist as a stable molecule since it cannot form a complete octet in its valence shell. It only has four valence electrons and cannot accommodate eight electrons around the carbon atoms. Therefore, it is a highly reactive molecule and tends to react with other compounds to form stable molecules.

On the other hand, options 1, 2, 3, and 5 (CH3OH, CH2O, CH3O, and C3H4) can form a complete octet in their valence shells, and they can exist as stable molecules.

Based on Lewis structures, the molecule that would probably not exist as a stable molecule among the given options is 3) CH3O.

Here's a step-by-step explanation:

1. Draw the Lewis structures for each molecule.
2. Check if each molecule has a complete octet (8 electrons) around each atom, with the exception of hydrogen which only needs 2 electrons.

Upon analyzing the Lewis structures:
1) CH3OH - Methanol - exists as a stable molecule with complete octets.
2) CH2O - Formaldehyde - exists as a stable molecule with complete octets.
3) CH3O - This molecule does not have a complete octet for the central atom (carbon) or the oxygen atom, making it unstable.
4) C2H2 - Acetylene - exists as a stable molecule with complete octets.
5) C3H4 - Propyne - exists as a stable molecule with complete octets.

Therefore, CH3O (option 3) would probably not exist as a stable molecule according to Lewis structures.

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a reaction is determined to be spontaneous at 25 c. does that mean it will automatically happen when you mix the reactants at 25 c?

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A spontaneous reaction at 25°C does not guarantee that it will automatically happen when the reactants are mixed at this temperature.

Spontaneity implies that the reaction is thermodynamically favoured, meaning it has a negative Gibbs free energy change (ΔG) under the specified conditions.

However, it does not necessarily imply that the reaction will occur rapidly. The reaction rate depends on factors such as activation energy, concentration, and catalyst presence, which affect the kinetics of the reaction.

While a spontaneous reaction at 25°C is thermodynamically favoured, it may not occur immediately when the reactants are mixed due to kinetic factors.

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A 50.0 g sample of liquid water at 25.0 °C is mixed with 19.0 g of water at 87.0 °C. The final temperature of the water is ________°C.

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The final temperature of the water after mixing a 50.0 g sample of liquid water at 25.0°C with 19.0 g of water at 87.0°C is 37.2°C.

What is the final temperature after mixing two samples of water with different temperatures and masses?

We can fix this problem by applying the idea of energy conservation. Assuming no heat is lost to the surroundings, the heat lost by the hot water (q1) must be equal to the heat gained by the cold water (q2):

q1 = q2

The equation for the heat lost or gained by an object is:

q = m * c * ΔT

where q is the heat lost or gained (in joules), m is the mass of the object (in grams), c is the specific heat capacity of the substance (in J/g°C), and ΔT is change in temp (°C).

Using this equation for both q1 and q2 and setting them equal to each other, we can solve for the final temperature (T-f).

q1 = m1 * c * ΔT1

q2 = m2 * c * ΔT2

where m1 is the mass of the hot water, ΔT1 is the temperature change of the hot water from its initial temperature to T-f, m2 is the mass of the cold water, and ΔT2 is the temperature change of the cold water from its initial temperature to T-f.

Putting the values, we get:

q1 = -q2

m1 * c * ΔT1 =

-m2 * c * ΔT2

(19.0 g) * (4.184 J/g°C) * (T-f - 87.0°C) = -(50.0 g) * (4.184 J/g°C) * (T-f - 25.0°C)

Solving for T-f, we get:

T-f = [(19.0 g) * (4.184 J/g°C) * (87.0°C) + (50.0 g) * (4.184 J/g°C) * (25.0°C)] / [(19.0 g) * (4.184 J/g°C) + (50.0 g) * (4.184 J/g°C)]

T-f = 37.2°C (rounded to two significant figures)

Therefore, the final temperature of the water is 37.2°C.

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A vessel holds a mixture of CO2, and N2 with a molar ratio of 1:2 at STP. The total volume of the gas mixture is 154.56 L. The mixture contains how many moles of CO2 gas and N2 gas respectively?

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The molar ratio of CO2 and N2 in the gas mixture is 1:2, which means that for every 1 mole of CO2, there are 2 moles of N2 in the mixture.

Let's assume that the number of moles of CO2 in the mixture is x. Then the number of moles of N2 is 2x, based on the molar ratio.

According to the ideal gas law, at STP, one mole of any gas occupies a volume of 22.4 liters. Therefore, if we know the total volume of the gas mixture, we can calculate the number of moles of the mixture using the formula:

moles = volume (in liters) / molar volume (22.4 L/mol)

In this case, the total volume of the gas mixture is given as 154.56 L. Substituting this value into the formula, we get:

moles of mixture = 154.56 L / 22.4 L/mol = 6.9 moles

Since the molar ratio of CO2 and N2 in the mixture is 1:2, we can set up the equation:

x + 2x = 6.9 moles

Simplifying the equation, we get:

3x = 6.9 moles

x ≈ 2.3 moles Therefore, the number of moles of CO2 gas in the mixture is approximately 2.3 moles, and the number of moles of N2 gas in the mixture is approximately 2 x 2.3 = 4.6 moles.

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