Answer:
because the soap and the water mix and make bubblesl
Explanation:
Write the nuclide symbol for Iodine-127. How many protons, electrons, and neutrons are in this isotope of iodine
Answer:
[tex]^{127}_{53} I[/tex]
53 protons and electrons and 74 neutrons.
Explanation:
Hello!
In this case, since the nuclide symbol of an isotope is represented by putting the atomic mass as a prefixed superscript and the number of protons as a prefixed subscript, for I-127 we have:
[tex]^{127}_{53} I[/tex]
Now we realize this isotope have 53 electrons and protons and the following number of neutrons:
[tex]neutrons= 127-53=74[/tex]
Notice this isotope has about the same molar mass of the average iodine atom.
Best regards!
A 0.67 gram sample of chromium is reacted with sulfur. The resulting chromium sulfide has a mass of 1.2888 grams. What is the empirical formula
Answer:
Cr₂S₃
Explanation:
From the question given above, the following data were obtained:
Mass of chromium (Cr) = 0.67 g
Mass of chromium sulfide = 1.2888 g
Empirical formula =?
Next, we shall determine the mass of sulphur (S) in the compound. This can be obtained as follow:
Mass of chromium (Cr) = 0.67 g
Mass of chromium sulfide = 1.2888 g
Mass of sulphur (S) =?
Mass of S = (Mass of chromium sulfide) – (Mass of Cr)
Mass of S = 1.2888 – 0.67
Mass of S = 0.6188 g
Finally, we shall determine the empirical formula of the compound. This can be obtained as follow:
Mass of Cr = 0.67 g
Mass of S = 0.6188 g
Divide by their molar mass
Cr = 0.67 / 52 = 0.013
S = 0.6188 / 32 = 0.019
Divide by the smallest
Cr = 0.013 / 0.013 = 1
S = 0.019 / 0.013 = 1.46
Multiply by 2 to express in whole number
Cr = 1 × 2 = 2
S = 1.46 × 2 = 3
Therefore, the empirical formula of the compound is Cr₂S₃
The empirical formula will be "[tex]Cr_2 S_3[/tex]".
Given:
Mass of Cr,
0.67 gramMass of product,
1.2888 gramsNow,
→ [tex]Mass \ of \ Sulphur = Mass \ of \ product -Mass \ of \ Cr[/tex]
[tex]= 1.2888-0.67[/tex]
[tex]= 0.6188 \ g[/tex]
then,
→ [tex]Moles \ ratio \ of \ Cr:S = (\frac{0.67}{51.996} ): (\frac{0.61888}{32} )[/tex]
[tex]= 0.0129: 0.0194[/tex]
[tex]= 2:3[/tex]
Thus the above response is right.
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The rate constant for the second-order reaction !s 0.54 M-1 s-1 at 300°C. How long (in seconds) would 1t take for the concentration of N02 to decrease from 0.62 M to 0.28 M?
Answer:
3.63s take for the concentration of NO₂ to decrease from 0.62M to 0.28M
Explanation:
The general equation for a second-order reaction is:
1/[A] = kt + 1/[A]₀
Where [A] is actual concentration of the reactant (0.28M)
k is rate constant (0.54M⁻¹s⁻¹)
t is time the reaction takes (Our incognite)
And [A]₀ is initial concentration of reactant (0.62M)
Replacing:
1/0.28M = 0.54M⁻¹s⁻¹t + 1/0.62M
3.5714 = 0.54t + 1.6129
1.9585 = 0.54t
3.63s = t
3.63s take for the concentration of NO₂ to decrease from 0.62M to 0.28Mwhich of the following elements would have the greatest difference between the first and the second ionization energies mg al k ca sr
Answer:
K
Explanation:
Ionization energy refers to the energy required to remove an electron from an atom. It usually increases across the period due to the increase in the size of the nuclear charge and decreases down the group due to increase in the number of shells.
If we look at the element, K, it has only one electron in its outermost shell. This implies that after this one electron is removed, the second ionization energy involves the removal of an electron from a filled shell.
This usually requires a lot of energy. Hence, the element having the highest difference in energy between first and second ionization energy is K.
what happened to the mixture as it is poured into the strainer with cloth?
Answer:
The solid particles will be trapped behind on the strainer while the liquid molecules will pass or filter through.
Explanation:
Filtration is a process of separation of mixtures involving an insoluble solid and a fluid such as liquids or gases using a filtering medium such as paper or cloth or any other material. During the process, the liquid molecules pass through the filtering medium whereas the solid particles are not allowed to pass through but are retained by the medium. The reason is that the pores on the filtering medium are only small enough for the liquid molecules to pass through but not the solid particles.
An example of a mixture that can be separated through filtration is a suspension of chalk and water. Also, a mixture of water and solid particles such as water and tea leaves can also be separated using a strainer with cloth.
In the question, if a mixture of insoluble solids in a liquid is passed through a strainer with cloth, the solid particles will be trapped behind on the strainer while the liquid molecules will pass through.
Filtration is a technique in which the solute and the solvent can be separated. This technique is based upon the size of the solute particle.
The solute to be separated should be insoluble in the solvent.In this process, the liquid solvent passes through the strainer while the solid particles or the solute remains on the top of the cloth.This is because the size of the solute is larger than the size of the filter that is cloth in this case.The liquid passes easily as the size of molecules of liquid is smaller than the size of the filtering medium.An example of filtration is the separation of tea leaves and water. The leaves will remain at the top of the strainer while the water will fall through the strainer into the cup.Therefore, if the mixture of insoluble solid is separated from a solvent then the solid will be retained on the cloth of the strainer while the liquid will flow through.
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please help me please help me
Answer:
formula of starch is (C6H10O5)n, where n is the number of glucose molecules in the chain.
Explanation:
Which type of plate boundary do you think is between the South American Plate and African Plate? How are the plates moving in relation to each other?
Answer:
The type of plate boundary between the South American Plate and the African Plate is a divergent one.
The two plates move apart from each other.
Explanation:
The boundary between the South American Plate and the African Plate is a divergent boundary. The plates moved, and between them, there is an oceanic basin. The plates move on top of the mantle, and magma goes up the divergent areas creating new surfaces when it solidifies. The new surface is called a ridge.
Consider the reaction Mg2Si (s) 4H2O (l) -> 2Mg(OH)2 (aq) SiH4 (g). Which of the reactants is in excess if we start with 50.0 grams of each reactant
Answer:
H₂O is the excess reactant
Explanation:
A reactant is in excess when the other reactant is over and the first reactant is still present.
For the reaction:
Mg₂Si (s) 4H₂O (l) → 2Mg(OH)₂(aq) + SiH₄ (g)
We need to convert mass of each reactant to moles in order to find which reactant is in excess as follows:
Moles Mg₂Si -Molar mass: 76.7g/mol-:
50.0g * (1mol / 76.7g) = 0.652 moles of Mg₂Si
Moles H₂O - Molar mass: 18.02g/mol-:
50.0g * (1mol / 18.02g) = 2.78 moles of H₂O
For a complete reaction of 2.78 moles of H₂O are required:
2.78mol H₂O * (1mol Mg₂Si / 4mol H₂O) = 0.694 moles Mg₂Si
As there are just 0.652 moles, Mg₂Si is limiting reactant and
H₂O is the excess reactant
what is the molarity of a solution made by adding 1.565 moles of PbNO3 to 500 mL
Answer:
[PbNO₃] = 3.13 M
Explanation:
Molarity is a specific sort of concentration where we have, the amount of solute's moles contained in 1 L of solution.
In this case, our solution's volume is 500 mL.
We convert to L → 500mL . 1L/1000 mL = 0.5L
Moles → 1.565 mol
Molarity (mol/L) → 1.565 mol / 0.5L = 3.13 M
There also types of concentration, for example molality which indicates the moles of solute in 1kg of solvent.
Determine the standard enthalpy of formation of SrI2(s) using a Born–Haber cycle. Enthalpy of sublimation of Sr(s) = 164 kJ/mol 1st ionization energy of Sr(g) = 549 kJ/mol 2nd ionization energy of Sr(g) = 1064 kJ/mol Enthalpy of sublimation of I2(s) = 62.4 kJ/mol Bond dissociation energy of I2(g) = 152.55 kJ/mol 1st electron affinity of I(g) = –295.15 kJ/molLattice energy of SrI2(s) = –1959.75 kJ/mol
Answer:
Enthalpy of formation of strontium chloride, SrCl = -558.1 kJ/mol
Explanation:
Sr(s) -------> Sr(g) ΔHsublimation = +164 kJ/mol
Sr⁺(g) -------> Sr⁺(g) First Ionization energy, IE₁ = +549 kJ/mol
Sr⁺(g) -------> Sr²⁺(g) Second ionization energy, IE₂ = +1064 kJ/mol
I₂(s) --------> I₂(g) ΔHsublimation = +62.4 kJ/mol
I₂(g) -------> 2I(g) Bond dissociation energy, BE = +152.55 kJ/mol
2I(g) ----> 2I⁻(g) Electron affinity, EA = 2 (-295.15 kJ/mol) = -590.3 kJ/mol
Sr²⁺(g) + 2I⁻(g) ------> SrI₂(s) Lattice energy, LE = -1959.75 kJ/mol
Overall equation for the formation of SrCl₂ is given as:
Sr(s) + I₂(s) ----> SrI₂(s) ΔHformation = ?
Enthalpy of formation, ΔHformation = (ΔHsublimation of Sr(s) + IE₁ + IE₂ + ΔHsublimation of I₂(s) + BE + EA + LE)
ΔHformation = {164 + 549 + 1064 + 62.4 + 152.55 + (-590.3) + (-1959.75)} kJ/mol
Sr(s) + I₂(s) ----> SrI₂(s) ΔHformation = -558 kJ/mol
Therefore, enthalpy of formation of strontium chloride, SrCl = -558.1 kJ/mol
Substance C has stronger attraction between molecules than substance D. If substances C and D are both in the gas phase and are at the same energy level, which of the two substances will need to have more energy transferred out in order to change to the liquid phase? Substance C or Substance D?
Answer:
Substance D would be the correct answer.
Which of the following are components of the anterior (ventralo body cavity?
-thoracic cavity
-vertebral cavity
-pleural cavity
-cranial cavity
Answer:
thoracic cavity
Explanation:
The ventral body cavity in human body is the front aspect of the human body. Ventral body cavity is combined with the combination of three components that include the thoracic cavity, the pelvic cavity and the abdominal cavity.
So, Thoracic cavity is the components of the anterior cavity that refers to the the ventral internal organs above the diaphragm.
Hence, the correct answer is "thoracic cavity".
Suppose a student conducted the synthesis of an alkyl ether and obtained 270 mg of the crude product. The student then used water/ethanol to recrystallize the product. After recrystallization, the mass of the alkyl ether product was 280 mg. What would be a possible explanation for the problem and what would be your suggestion to the student
Answer:
The alkyl ether was yet to be totally dried off after the student recrystallize it .
The suggestion to the student is to redry the alkyl ether product and then reweigh
Explanation:
Based on the information the likely explanation for the problem that arise is that the alkyl ether was not totally dried after the student recrystallize the product which lead to the increase in mass from 270mg to 280mg gaining extra mass of 10mg (270mg -280mg).
Therefore what would be my suggestion to the student is that they should redry the alkyl ether product again and make sure that the water is totally dried off and then reweigh or weigh the product again for the second time .
(GIVING BRAINLIEST)Match the type of chemical bond with the best description:
A.) ionic bonding
B.) covalent bonding
C.) metallic bonding
-------------------------------------------
1.)sea of electrons surrounding metal cations
2.) sharing of electrons between nonmetal atoms
3.) transfer of electrons from cation to anion
Answer:
A and 3
B and 2
C and 1
Explanation:
Ionic bonding is the transfer of electrons from a cation to an anion.
Covalent bonding is the sharing of electrons between nonmetal atoms.
Metallic bonding is the sea of electrons metal cations.
Hope this helped!
How many moles are in 123.0 grams of KClO4? (3 points)
0.2354 mol KClO4
0.6445 mol KClO4
0.7124 mol KClO4
0.8878 mol KClO4
Answer:
0.8878 mol KClO4
Explanation:
Molar mass of KClO4 = 39.0983 + 35.453 + ( 15.9994 x 4 ) = 39.0983 + 35.453 + 63.9976 = 138.5489g/mol
but,
number of moles = mass in grams / molar mass where mass in grams = 123g, molar mass = 138.5489g/mol
number of moles = 123g / 138.5489g/mol = 0.8878mol
Therefore the number of moles present in 123 g of [tex] KClO_4[/tex] is 0.888 moles.
Given,
The weight of the [tex] KClO_4[/tex] is 123. grams
molecular weight of [tex] KClO_4[/tex] is [tex]39+35.5+16\times4=138.5 g[/tex]
138.5 g of [tex]KclO_4[/tex] is equal to one mole
Gram molecular wt. of a substance is equal to one mole
No. of moles = [tex]\frac{Wt}{GMW} [/tex]
123 g of [tex]KClO_4[/tex] is equal to [tex]\frac{123}{138.5}=0.888 moles [/tex]
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A solution containing a mixture of lactic acid and lactate was found to have a pH of 4.34. Calculate the ratio of the lactate concentration to the lactic acid concentration in this solution.
Answer:
3.02
Explanation:
Step 1: Given and required acid
pH of the solution: 4.34
pKa of lactic acid: 3.86
Step 2: Calculate the ratio of the lactate concentration to the lactic acid concentration in this solution
We have a buffer system formed by a weak acid (lactic acid) and its conjugate base (lactate ion). We can find the ratio of the lactate concentration to the lactic acid concentration in this solution using the Henderson-Hasselbach equation.
pH = pKa + log [lactate]/[lactic acid]
4.34 = 3.86 + log [lactate]/[lactic acid]
[lactate]/[lactic acid] = 3.02
Which of the following is true about properties of covalent/ molecular bonds?
Are formed between metals only
Weak bonds
Are formed between metals and non-metals
Strong bonds
Answer:There are two types of atomic bonds - ionic bonds and covalent bonds. They differ in their structure and properties. Covalent bonds consist of pairs of electrons shared by two atoms, and bind the atoms in a fixed orientation. Relatively high energies are required to break them (50 - 200 kcal/mol). Whether two atoms can form a covalent bond depends upon their electronegativity i.e. the power of an atom in a molecule to attract electrons to itself. If two atoms differ considerably in their electronegativity - as sodium and chloride do - then one of the atoms will lose its electron to the other atom. This results in a positively charged ion (cation) and negatively charged ion (anion). The bond between these two ions is called an ionic bond.
Newton's Second Law: Acceleration
Your dog's wagging tail knocks over the cup of pencils sitting on your desk.
What kind of force is his tail?
1.an unbalanced force
2.an inert force
3.gravitational force
4.friction
Answer:
an unbalanced force
Explanation:
When methane is combusted in the presence of oxygen, water and
carbon dioxide are produced. State a practical use foe this reaction.
At midnight in the dark of the night, what is most likely happening in a leaf? * O Respiration O Photosynthesis O Both photosynthesis and respiration Neither photosynthesis or respiration
Please help thanks!
Answer: Photosynthesis
Explanation:
Answer:2
Explanationb
Which change happens during evaporation?
A. A gas turns into a liquid.
B. A liquid turns into a gas.
C. A solid turns into a liquid.
D. A liquid turns into a solid.
Answer:
B.) A Liquid turns into Gas.
Calculate the mass of water produced when 1.43 g of butane reacts with excess oxygen. Express your answer to three significant figures and include the appropriate units. g
Answer:
[tex]m_{H_2O}=2.22gH_2O[/tex]
Explanation:
Hello!
In this case, since the combustion of butane is:
[tex]C_4H_{10}+\frac{13}{2} O_2\rightarrow 4CO_2+5H_2O[/tex]
As there is an excess of oxygen, we can compute the mass of water by simply using the molar masses of butane and water and the 1:5 mole ratio between them as shown below:
[tex]m_{H_2O}=1.43gC_4H_{10}*\frac{1molC_4H_{10}}{58.14gC_4H_{10}} *\frac{5molH_2O}{1molC_4H_{10}} *\frac{18.02gH_2O}{1molH_2O} \\\\m_{H_2O}=2.22gH_2O[/tex]
Best regards!
Annie learns that the compound sulfuric acid is called the universal chemical. The acid is used in everything from gasoline to paper. Annie uses beads in three different colors to model sulfuric acid. Based on the model, what is the chemical formula of sulfuric acid?
A.
S2HO4
B.
O2H4S
C.
S4O2H
D.
H2SO4
Answer:
D. H2SO4
Explanation:
The chemical formula of a compound is an expression that stares out the elements (in form of symbols)present in a compound and the number of the atoms.
In the image;
There is one sulphur (S) atom, 4 oxygen(O) atoms and 2 hydrogen (H) atoms
The chemical formula is;
H2SO4.
The correct option is option D.
The liquid soaking the dollar bill is a mix of alcohol and water. As the alcohol burns, the water evaporates. Why doesn't the heat from the burning alcohol cause the bill itself to char or burn
Answer:
Because heat causes alcohol to volatilize, instead of burning it.
The combustion is not fulfilled since this is detached from the surface of the banknote that would be the necessary product to burn, in addition to considering that the necessary temperature is not reached
Explanation:
When water and alcohol are joined, they form a solution with high evaporation power, plus alcohol that has a higher degree of volatility than water, this is how these liquids are not retained on the surface of the banknote with heat and they are not it burns.
Which of the following best illustrates an ABIOTIC factor in the
environment affecting a BIOTIC factor?
a very strong Abiotic factor in the world is the sun it let's off vitamin d and it can burn humans to were you get skin cancer so the sun
Calculate the gravitational force of attraction between a 26kg boy and his 5.1kg dog when they are separated by 0.19m
Answer:
Gravitational force of attraction G(f) = 2.44 x 10⁻⁷ (approx.)
Explanation:
Given:
Mass M1 = 26 kg
Mass M2 = 5.1 kg
Distance r = 0.19 m
Find:
Gravitational force of attraction G(f)
Computation:
Gravitational force of attraction G(f) = G(m1)(m2)/r²
Gravitational force of attraction G(f) = [6.67 x 10⁻¹¹](26)(5.1)/(0.19)²
Gravitational force of attraction G(f) = 8.84 x 10⁻⁹ / 0.0361
Gravitational force of attraction G(f) = 2.44 x 10⁻⁷ (approx.)
what happens to change the solubility when you added 6.0 M HCl to the second test tube with benzoic acid
Answer:
It becomes insoluble again.
Explanation:
The chemical equation showing the reaction between benzoic acid, and sodium hydroxide,NaOH is given below;
C6H5COOH + NaOH ------------------------> C6H5COO^- Na^+ + H2O.
The Benzoic acid, C6H5COOH is insoluble but when it reacted with 1M Sodium hydroxide, NaOH it changes to sodium benzoate, C6H5COO^- Na^+ which is more soluble than the benzoic acid.
C6H5COO^- Na^+ + HCl -------------------> C6H5COOH + NaCl.
When the sodium benzoate, C6H5COO^- Na^+ reacts with 6M HCl, it is converted back to benzoic acid which is insoluble. Hence, precipitation is observed.
Question 10 of 10
Choose the option which best answers the
question.
Which of the following is not equivalent to
one drink?
a. 12 oz. of beer
b. 5 oz. of wine
c. 4 oz. of 40-proof liquor
d. 1 1/2 oz. of 80-proof liquor
Answer:
d 1 1/2 oz.. of 80-proof liquor
1 1/2 oz. of 80-proof liquor is not equivalent to one drink. Hence, option D is correct.
What is oz?Oz is an abbreviation for ounce. An ounce is equal to 1/16 pound (437 1/2 grains) and equal to 480 grains, or 1/12 pound.
1 1/2 oz. of 80-proof liquor is not equivalent to one drink.
Hence, option D is correct.
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When testing a hypothesis, what type of data can be taken?
Answer:
visual ob
Explanation:
Answer:
all of the above
because these use all of your 5 senses
Can someone help me with this question?
Answer:
I think the answer is h
Explanation:
when you let the balloon go, all the air the is inside comes out causing it to move forard
