Chemical reactions that release heat energy are called exothermic reactions. example:
What is exothermic and endothermic reaction?C(g)+O2(g)→CO2(g)+thermal energy. A chemical reaction that absorbs heat energy is called an endothermic reaction. example:
CaCO3Heat→CaO+CO2.
A chemical reaction or physical change is endothermic when the system absorbs heat from the environment. In an endothermic process, the system gains heat from the environment and reduces the temperature of the environment.
A chemical reaction that releases energy is called exothermic. In an exothermic reaction, more energy is released in forming bonds within the products than is expended in breaking bonds within the reactants. Chemical reactions that absorb (or consume) energy are called endothermic.
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arrange tha following substances in order of increasing boiling point and increasing solubility in water. -2-butanol ,-2-propanol,-2-methylpropane, -2-pentanol
Answer:
Here is the order of increasing boiling point and increasing solubility in water for the substances you listed:
-2-Methylpropane < -2-butanol < -2-pentanol < -2-propanol
Explanation:
-2-Methylpropane has the lowest boiling point and is the least soluble in water.
-2-butanol has a higher boiling point than -2-methylpropane, but lower than -2-pentanol and -2-propanol
-2-pentanol has a higher boiling point than -2-butanol and -2-methylpropane, but lower than -2-propanol
-2-propanol has the highest boiling point and is the most soluble in water.
Please note that this is a general trend and there can be variations depending on factors such as pressure, purity of the substance, and temperature.
Can you help me with this question
Following are the scientific methods asked in question -
Christina decides to test the idea of her friend Anders that different metals make characteristic colors in flame. She mixes up a variety of metal solutions, then dips steel wires into each and puts each wire into a flame, noting the color of the flame in her record of this experiment.After much experimentation, John discovers a law which says that the wavelengths of light absorbed by hydrogen gas fit into a pattern which he is able to express in a mathematical formula. Niels has a hypothesis about why the wavelength of light absorbed by hydrogen has a certain value. Niels suggests the orbit of the electron in the hydrogen atom can only have certain radii, and when the electron "jumps" from one orbit to another, it emits light of an energy corresponding exactly to the difference in orbit energies.What are Scientific methods?The scientific method, an empirical technique of learning, has governed the development of science from at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific method for additional detail.)
It takes thorough observation and the use of strong skepticism regarding what is observed because one's perception of the observation may be influenced by cognitive presumptions. It entails creating hypotheses using induction based on these observations, testing the accuracy of those hypotheses using experimental and measurement-based statistical testing of the inferences drawn from them, and then adjusting (or discarding) those hypothese in light of the experimental findings.
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A 0.1 M solution is diluted by three orders of magnitude. What is the new concentration?
Answer:
So the new concentration of the solution is 0.0001M
Explanation:
To dilute a solution by three orders of magnitude, we need to add 3 zeroes, that is 10^3 times the original volume.
The new concentration would be 0.1M / (10^3) = 0.0001M (4 sig figs)
So the new concentration of the solution is 0.0001M
what volume (mL) contains 4.350g of isopropyl alcohol if it's density is 0.78g/ml
give answer in decimals
Answer: 5.5769g/ml^3
Explanation:
density=mass/volume
.78g/ml=4.350g/volume
What volume is 0,3 N. acid solution is required to
neutralize a solution containing 0,32 g of NaOH in 40 cm³?
(Answer: 26,6 cm³) how??
The volume required of 0,3 N. acid solution to neutralize solution containing 0,32 g of NaOH in 40 cm³ is 26.66cm³.
How to calculate volume?N1V1 = N2V2
normality = molarity x basicity
For sulfuric acid, the basicity is 2.
∴N1=0.3N
V1=?
Normality of NaOH is [0.32/(40×40)]×1000
N2=0.2×1=0.2N
V2=40ml
0.3 x V1 = 0.2 x 40
V1 = 26.6 cm³
What is normality?It is defined as the number of moles per liter of solution. It is used to measure gram equivalents to the total volume of the solution. It is used to measure the ratio of the number of moles in the total volume of the solution. The unit of normality is N or eq L-1.
The standard concentration (normality, CN) of a solution is always greater than or equal to the molarity (molarity, CM) of the solution.
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MNRLDZIAEEI ___________________ remains of organisms, or fossils, show how
long-dead organisms lived and how their bodies were SDTETRRUCU
Answer:
the flesh decay
but their bone remains
Which has more moles in the sample: a sample of 0.2 moles of KI or a sample of 3.2x102^3 atoms of MgO? MUST SHOW WORK
3.2x10^23 atoms of MgO would have more number of moles as shown.
What is the number of moles?We know that the number of moles is a concept that we can be able to glean from Avogadro. The idea of mole has to do with the amount of substance that contains the same number elementary entities as what we have in carbon 12.
We have been told that we are to compare 0.2 moles of KI and then we also look at 3.2x10^23 atoms of MgO. We would then have to find the number of moles that we are going to have in the 3.2x10^23 atoms of MgO as we have written here.
If 1 mole contains 6.02 * 10^ 23 atoms
x moles would contain 3.2x102^3 atoms
x = 1 mole * 3.2x10^23 atoms/ 6.02 * 10^ 23 atoms
x = 0.53 moles
Hence the number of moles in the KI is less than that in the MgO.
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A gold bullion dealer advertised a bar of pure gold for sale. The gold bar had a mass of 3300 g and measured 2.00 cm x 15.0 cm x 6.00 cm. Calculate the density of the bar. Was the bar pure gold? (Hint: The density of pure gold is 19.3 g/cm3)
The denstiy of the gold bar of mass 3300 g is 18.3 g/cm³.
What is density?Density is the ratio of mass and volume.
To calculate the density of the bar gold, we use the formula below.
Formula:
D = m/lwh........................ Equation 1Where:
D = Densitym = Massl = Lengthw = Widthh = HeightFrom the question,
Given:
m = 3300 gl = 2 cmw = 15 cmh = 6 cmSusbtitute these values into equation 1
D = (3300)/(2×15×6)D = 18.3 g/cm³The bar is not a pure gold.
Hence, the denstiy is 18.3 g/cm³.
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3.15 g of nitrate is obtained from 1.35 g of metal oxide.
Calculate the equivalent mass of this metal.
Answer:
Explanation:
The equivalent mass of the metal can be calculated using the following equation:
Equivalent Mass = (3.15 g Nitrate)/(1.35 g Metal Oxide) * (1 mole Nitrate)/(1 mole Metal Oxide)
Using the molar masses of nitrate (NO3) and metal oxide (MO):
Equivalent Mass = (3.15 g NO3)/(1.35 g MO) * (1 mol NO3)/(1 mol MO)
= (3.15 g NO3)/(1.35 g MO) * (62.00 g NO3)/(molar mass of MO)
The molar mass of the metal oxide (MO) must be known to calculate the equivalent mass of the metal.
What mass of HNO3 was contained in the solution if 35
cm3. of 0,4 N was required to neutralize it? NaOH solution?
What is the titer of a NaOH solution?
(Answer: 0,882 g, 0,016 g/
cm³.)
The mass of the HNO3 solution was found to be 0.882 g and the titer of the NaoH solution was 0.016g/cm^3.
what was NaoH ?
The inorganic chemical sodium hydroxide, widely known as lye and caustic soda, has the formula NaOH. It is a white solid ionic compound that contains sodium cations Na+ and hydroxide anions OH.
Sodium hydroxide is a caustic base and alkali that degrades proteins at room temperature and can inflict serious chemical burns. It collects moisture and carbon dioxide from the air and is extremely soluble in water. It creates a succession of NaOHnH2O hydrates. Between 12.3 and 61.8 °C, the monohydrate NaOHH2O crystallises from water solutions. This monohydrate is frequently used in commercially available "sodium hydroxide," and published data may refer to it instead of the anhydrous component.
As one of the most basic hydroxides, sodium hydroxide is commonly employed in conjunction with neutral water.
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When this compound was placed in a flame test, an orange color was seen. When mixed with NaOH, a milky white precipitate was formed. When mixed with hydrochloric acid, bubbles were produced. Determine the name and formula of this compound.
The name of the compound is calcium chloride and the chemical formula of the compound is CaCl₂.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
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The q of a system that releases 12.4J of heat to surroundings is _____J.
a.) 12.4
b.) -12.4
c.) 0
d.) not enough info
If you explain why I'll give brainly!!
Answer: B.) -12.4
Explanation: This is because the sign of heat transfer is determined by the system's perspective. In this case, the system is releasing heat to the surroundings, which means that heat is flowing out of the system, making the heat transfer negative. The magnitude of the heat transfer is 12.4 J.
a 100um thick layer of gold is plated on a medallion that is 4.00cm in diameter and 2.00mm thick. What is the volume of gold plated in cm^3?
The volume of the gold plates in cm₃ is 2.513274 cm₃
What is volume?Volume is the space occupied by a three-dimensional object“”
Volume = {mass} {density}
Given that the thickness or height of medallion, h = 2 mm = 0.2 cm
Diameter of the medallion, d = 4 cm
Radius of medallion, r = d/2 = 2 cm⁻³
The thickness of the gold plating, x = 1 μm = 10⁻⁴ cm
The density of gold = 19.3 g cm
Now we know that the shape of a medallion is cylindrical.
Hence, the volume of the medallion before platting,
Vbefore = π.r2.h = π.(2)2.0.2 = 2.513274 cm₃
Therefore, the volume of the gold-plated is 2.513274 cm₃.
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How many atoms are in one mole of the following:
1.0
2.02
3. Na
4. NaCl
Answer:
Explanation:
The number of atoms in one mole of a substance is called Avogadro's number and is approximately 6.022 x 10²³ atoms/mol.
There are 2.02 moles of atoms in one mole of a substance.
The number of atoms in one mole of Na (sodium) is 6.022 x 10²³ atoms/mol
In one mole of NaCl (sodium chloride), there are 6.022 x 10²³ atoms of sodium and 6.022 x 10²³ atoms of chlorine, for a total of 12.044 x 10²³ atoms.
I need help answering this please IUPAC
Answer:
3,3 dihydroxy
Oh group attach with that benzene ring
A 20 N force pulls to the right and friction pulls 5 N. If the mass is 5 kg, find acceleration
Answer:
Explanation:
Force = Mass x Acceleration
(20 - 5)N = 5kg x Acceleration
Acceleration = 15/5
= 3 N/kg
The following table lists molar concentrations of seven major ions in seawater. Using a density of 1.022 g/ml. for seawater, convert the concentrations
for the two ions in the question below into molality.
The sodium ion:
The sulfate ion:
The molality of the sodium ions and the sulfate ions are 44.5 and 10.66 respectively.
How do you calculate molality?
The total number of moles of solute per litre of solution is defined as the molarity of a specific solution. Because, unlike mass, the volume of a system changes with changes in physical circumstances of the system, the molality of a solution is reliant on changes in physical qualities of the system such as pressure and temperature. M, which stands for molarity, represents molarity. The molarity of a solution is one molar when one gramme of solute is dissolved in one litre of solution. As we know, the solvent and solute combine to create a solution, hence the total volume of the solution is measured.
molality of sodium was
=480.57/10.781
=44.5
molality of sulfate was
=28.93/2.712
=10.66
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How much ice in grams at 0°C would have to melt to lower the temperature of 350 mL of water from 24°C to 6°C ? Assume the density of water is 1.0 g/mL.
In order to lower the temperature of 350 mL of water from 24°C to 6°C, we need to calculate the amount of heat energy that needs to be removed from the water. We can use the formula:
Q = mcΔT
where Q is the heat energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
The specific heat capacity of water is 4.184 J/g°C. Since the density of water is 1.0 g/mL, the mass of 350 mL of water is 350 g.
Q = (350 g) (4.184 J/g°C) (18°C)
Q = 30,276 J
To remove this much heat energy, we can use ice to cool the water. The heat of fusion of water is 333.55 J/g, which is the amount of heat energy required to melt one gram of ice at 0°C.
Q = (m)(333.55 J/g)
m = Q / 333.55 J/g
m = 30,276 J / 333.55 J/g
m = 90.4 g
So, 90.4 grams of ice at 0°C would have to melt to lower the temperature of 350 mL of water from 24°C to 6°C.
A student mixes baking soda with acetic acid in a test tube. The student observes the formation of a gas and records the two reactions that occur.
The student concludes that the two reactions follows the Law of Conservation of Matter. Which statement supports the student's conclusion?
The number of atoms in the reactants and products of each reaction is the same. The last option.
Law of conservation of matterThe law of conservation of matter states that during chemical reactions, matter can neither be created nor destroyed but can be converted from one form to another. This law is also applicable to energy and atoms during chemical reactions.
In other words, all chemical reactions, as a rule of thumb, obey the law of conservation. Thus, for any chemical reaction:
Energy is conservedMatter is conservedThe number of atoms of different elements is conservedTherefore, the statement that supports the student's conclusion that the two reactions follows the law of conservation of matter would be that the number of atoms in the reactants and products of each reaction is the same.
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5.22 2.61(g - 7)
g
=.
HELP PLS
Answer:
g = 9
Explanation:
5.22 = 2.61(g - 7) ==> solve for g
5.22 / 2.61 = 2.61(g - 7) / 2.61 ==> divide both sides by 2.61 to isolate g
2 = g - 7 ==> simplify
9 = g ==> add 7 on both sides
g = 9
How many gold atoms are in a 0.330 ounce, 18K gold bracelet? (18K gold is 75% gold by mass.)
The number of gold atoms in 0.330 ounce, 18 K gold bracelet would be 2.12 x [tex]10^{22[/tex] atoms of gold.
Number of atoms in substances1 ounce = 28 grams
0.330 ounce = 0.330 x 28 = 9.24 grams
18 K gold = 75% gold = 9.24 x 0.75 = 6.93 grams
In other words, a 0.330-ounce, 18 K gold bracelet contains 6.93 grams of actual gold.
Mole of 6.93 gold = 6.93/196.967 = 0.0352 mol
1 mole = 6.022 x [tex]10^{23[/tex] atoms
0.0352 mole = 0.0352 x 6.022 x [tex]10^{23[/tex]
= 2.12 x [tex]10^{22[/tex] atoms
In other words, a 0.330-ounce, 18 K gold bracelet contains 2.12 x [tex]10^{22[/tex] atoms of gold.
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A student made a sketch of a potential energy diagram to represent an endothermic reaction.
Explain, using complete sentences, why the diagram made by the student is correct or incorrect. Be sure to also explain what the values of X and Y represent. (10 points)
Answer:
The student's diagram is correct. The potential energy on the x-axis is increasing, and the potential energy on the y-axis is decreasing, which accurately displays an increase in energy (heat) being absorbed by the reaction. The value of X represents the energy of the reactants, while the value of Y represents the energy of the products. This indicates the reaction is endothermic, as the reactants have a lower energy than the products, meaning energy had to be absorbed from the environment in order to reach a stable state.
6. Write the mole ratios for the reaction of hydrogen gas and oxygen gas, 2H₂(g) + O₂(g) → 2H₂O. Make a sketch of six hydrogen molecules reacting with the correct number of oxygen molecules. Show the water molecules produced.
Answer:
hi there in this question. We are given the balanced equation for the reaction of water from hydrogen gas and oxygen gas. And the first thing we want to know is the mole ratio for this reaction. So we get the mole ratio from the coefficient in the balanced equation. And if there's not a coefficient written, it's understood that it's a one. So that means our mole ratio here is going to be two moles of hydrogen. Because coefficient is two Reacts with one mole of oxygen because its coefficient is one to produce two moles of the water. And we know it's a two because its coefficient as a two. Alright, so this would be the mole ratios for these, The hydrogen and oxygen react in a 2-1 ratio, producing two moles of the water. Alright, so now we want to sketch what's going to happen here if we start with six hydrogen molecules and the correct number of oxygen molecules. So our hydrogen molecules six of those remember their H two. So that would just be one hydrogen molecule that I just drew there. These are gasses. So they're going to be randomly spaced, moving around. There's three, there's 4. Here's five and six. All right, so, we know these react in a 2-1 ratio. So for every six of these We would only need half as many or three of the 02s. So here's one oxygen molecule. Again, this is a diatonic also. So each molecule is composed of two oxygen atoms. Alright, So we have that reacting with that. And when these combined we are going to get six water molecules and we know that because we started with six hydrogen and looking at our mole ratio for every two hydrogen that we start with, we can make to water. So if we start with six hydrogen We can make six water. So our oxygen molecules, the bonds between them were broken during this reaction and each one bonded 22 hydrogen apps. Because the bonds between the hydrogen molecules, we're also broken and we've rearranged to form six water molecules. Alright, so that would be our finished sketch showing the hydrogen. six molecules of the hydrogen Reacting with three molecules of the oxygen to produce six molecules of water. So these are reacting in that proper ratio of 2-1 22.
Explanation:
i hope this helped :)
The value of the Euro was recently $1.35 U.S. and the price of 1.00 liter of gasoline in France is 1.42 Euro. How many gallons of gas can you buy in France for $1.00?
To form a 1:1 ratio through ionic bonding, an element in group 1A would need to react with an element in group 7A.
True
False
When Aluminum reacts with oxygen, it would take 3 aluminums and 1 oxygen atoms to become stable by all atoms in that compound having filled outer shells.
True
False
First group metals forms 1:1 compounds with 17th group or group 7 A. Thus, the statement is true. Aluminum forms its oxides by 2 Al and 3 oxygen atoms. Hence, the statement is false.
What is ionic bonding ?Ionic bonds are formed between metals and non metals. Metals are electron rich and easily loss one or more electrons to electron deficient nonmetals.
First group elements are called alkali metals. They have one valance electron. Group 7A are halogens with 7 valence electrons. They need one more electron to achieve octet.
Thus, alkali metals donate their valence electron to halogens and forms 1:1 compound. Therefore, the statement is true.
Aluminum reacts with oxygen to form its oxide Al₂O₃. Thus, 2 Al and 3 Os are combined to form covalent bond. Thus, the statement is false.
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Select which element(s) contain atoms at ground state with 4 electron layers
HELP PLEASE!
Answer: Cobalt,Titanium,Potassium
Explanation:
If an element has 4 electron layers can be well understood from their electronic configuration :-
Cobalt -> [Ar] 3[tex]d^{7}[/tex] 4[tex]s^{2}[/tex]
Titanium -> [Ar] 3[tex]d^{2}[/tex] 4[tex]s^{2}[/tex]
Carbon -> [He] 2[tex]s^{2}[/tex] 2[tex]p^{2}[/tex]
Potassium -> [Ar] 4[tex]s^{1}[/tex]
Determine the average density if the results for three trials were: 3.5512 g/mL, 3.4188 g/mL and
3.8617 g/mL.
Answer:
3.6106 g/mL (approx.)
Explanation:
Average density = Sum of all densities/ Number of Densities
Which is, (3.5512 + 3.4188 + 3.8617)/3
≈ 3.6106 g/mL
How are gases ionize in a plasma globe?
Answer:
Plasma globes use high voltage, low current electrical discharges to ionize gases, typically a mixture of noble gases such as argon and neon, inside the globe. The electrical discharge excites the gas atoms, stripping them of their electrons to create a cloud of positively charged ions and negatively charged electrons, also known as plasma. The electrical discharge arcs between the electrodes in the globe, creating the colorful, dancing lights that are characteristic of plasma globes.
Explanation:
Which of the following chemicals is an example of a perovskite that would be used in a perovskite solar cell?
Answer:
CH3NH3Pbl3
Explanation:
is an example of a perovskite th that would be used in a perovskite solar cell
Holide Perovskite
indicate the types of forces that are involved between the solute and solvent when forming a homogeneous solution between lino3 and h2o .
The types of forces that are involved between the solute and solvent when forming a homogeneous solution between LiNO₃ and H₂O is ion-dipole forces dispersion forces dipole-dipole forces hydrogen bonding.
The relatively weak attractive forces that is acting on neutral atoms and other molecules as a result of the electric polarization induced in each particle by the presence of other particles. Forces like hydrogen bonding, dispersion forces, and dipole-dipole interactions are all examples of van der Waals forces.
Generally, the kinds of intermolecular forces that are involved in solution formation are dispersion forces, dipole-dipole forces, hydrogen bonding, and ion-dipole forces.
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