Chemistry Chapter 3

H2O

6

CH2O Percent Mass

6.71%

Which of the following pieces of information do you need to calculate the molecular mass of a compound? Select all that apply

- The atomic mass of each element contained in the compound - The formula of the compound

CHCL3

This molecule contains 12.01 amu of carbon, 1.008 amu of hydrogen, and 106.35 amu of chlorine

Percent yield

actual yield/ theoretical yield X 100

H2O

dissolves in water

substances to the right of the arrow

product

Which of the following statements correctly interpret the balanced chemical equation 4HCL (aq) + Mn02 (s)--->MnCl2 (aq) +2H2O(g) + Cl2(g)?

-HCl is a reactant in this equation -The MnCl2 produced is dissolved in water

CH3OH percent mass

12.6%

Al(OH)3

2

The molecular formula of a compound having an empirical formula NH2 (M=32.05 g/mol) is N ___ H4 ____

2, 4

substance to the left of the arrow

reactant

Correctly define the atomic mass of an element

The average of the masses of the natural isotopes of the element, according to their abundance

Given the balanced equation 2Al(s) +3cl2(g)----> 2AlCl3(s), select all the conversion factors that correctly represent the molar relationship in this equation

-2 mol AlCl3/3 mol Cl2 -2 mol Al/3 mol Cl2

Give the correct procedure to calculate the mass of a substance given the number of moles?

moles X molar mass

Correctly ordered the steps necessary to calculate the mass of product formed in a chemical reaction, given the masses of all react unts. Start with the 1st step at the top of the list

- Determine the moles of each reactant present by dividing its mass by its molar mass - Determine the amount of product that could be formed from each reactant using the appropriate mole ratios - I identify the limiting reactant as the reactant that produces the least amount of product - To find the mass, multiply the number of moles product formed (from the limiting reactant) by the molar mass of the product.

What following actions are permitted in balancing a chemical equation?

-Multiplying all coefficients by a common factor - Inserting coefficients and front of formulas of reactants and products

Correctly describe atomic mass and atomic mass units

-The atomic mass of an element can be read from the periodic table -The atomic mass unit is defined as 1/12th of the mass of a carbon-12 atom.

CCl4

1 mole of this substance contains 1 mol of carbon and 4 moles of chlorine

CH2Cl2

1 mole of this substance contains 12.01 G of carbon, 2.016 G of hydrogen, and 70.90 G of chlorine

Place the steps necessary to balance a chemical equation correctly in order, starting with the final step at the top of the list

1) Place reactant on the left of the reaction arrow, and products on the right 2) Balance the Atoms 3) Adjust the coefficients such that there are the smallest whole- number at coefficients 4) Do a final check to make sure the equation as balanced

Correctly arrange the steps in order for calculating the molar mass of H2SO4. Place the 1st step at the top of the list

1) The molecular mass of H2SO4=(2 x the atomic mass of H)+(the atomic mass of S) + (4 x the atomic mass of O) 2) The molecular mass of H2SO4= (2 x 1.008 amu) + (4 x 16.00 amu) 3) The molecular mass of H2SO4 =98.09 amu

The balanced equation 2S(s)+302(g)---->2SO3(g) is given. The number of moles of SO3 that will form from the complete reaction of 1.5 mol of O2 is given by________.

1.5 mol O2 X 2 mol SO3/ 3 mol O2

Identify the whole number coefficients required to balance the chemical equation SO2(g)+ O2(g)--->SO3(g) correctly. ( Enter all numbers, including the digit 1 if required, and make sure you have the simplest ratio of coefficients.)

2 SO2 1 O2 2 SO3

When hydrogen gas is passed over powderes iron(III) oxide, iron metal and water vapor are formed. Which are the following is the correct balanced a equation for this process?

3H2(g)+Fe2O3(s)-->2Fe(s)+3H2O(g)

Atomic masses are commonly read from the periodic table to____ significant figures. The atomic mass of H is therefore is equal to ______ amu, whereas the atomic mass of C is equal to ______ amu. Use the periodic table given and your textbook to answer the question.

4, 1.008, 12.01

How many grams of KMnO4 correspond to 3.13 x 10^22 formula units of KMnO4? Avagadro's number is 6.022 x10^23.

8.21g of KMnO4

Reactant

A starting material in a chemical reaction

Product

A substance formed as the result of a chemical reaction

Molecular Mass

The sum of atomic masses of the elements in a molecule of the compound

Correctly describe the molecular mass of a compound?

The sum of the atomic masses of all the elements of a compound

The _______ mass of a substance is the mass per mole of its entities, where the term, "entities" can describe_______, ions, molecules, or formula units

molar, atoms

The ________ is the SI unit that expresses the amount of substance. Specifically, it is defined as the amount of substance containing the same number of entities as the number of________ in exactly 12g of carbon-12.

mole, atoms

Formula mass

the sum of the atomic masses in a formula unit of the compound

---->

to yield

Which of the following provides the correct mathematical operation to calculate the number of molecules and 2.0 mol of CH4?

2.0mol X 6.022 X 10^23 molecules/mol

Theoretical yield

The amount of product calculated from the molar ratio in the balanced chemical equation

Al2S3

1

The molar mass of a monotonic element is the numerical value listed on the periodic table expressed in units of g/_______. For example, the molar mass of calcium(Ca) is __________ with units of g/___________. ( Remember to round to 4 significant digits.)

mol, 40.08, mol

Actual yield

Amount of product obtained experimentally from a chemical reaction

Which of the following statements describe the information that can be gained from a balanced chemical equation?

- The relative quantity(moles) of substances involved - The identities of substances involved - The physical States of reactant and products, often

Calculate the correct number of moles and formula units and 7.3 × 10^3 g of CaSO4-. Avogardos number is 6.022 x 10^23

-3.2 x 10^19 formula units of CaSO4 -5.4 x 10-5 moles of CaSO4

C6H6 percent mass

7.74%

Which one of the following options gives the correct procedure to calculate the number of moles of a substance given the mass?

Given mass/ Molar mass

Would you the following statements correctly describe the atomic mass of carbon?

- The average atomic mass of the carbon -12 isotope is 12.0 amu - The average atomic mass of carbon is 12.01 amu

Given the balanced equation equation Ag2S(s)+2HCL(aq)---> 2AgCl(s) + H2S(g), determine the moles of HCL required and the mass of AgCl formed from the complete reaction of 18.3g of Ag2S.

-21.2g of AgCl are formed -0.148 mol HCL are required

H2S

3

Which reflects Avogadros number?

6.022 x 10^23/ 1 mol

Arrange the necessary steps in order for finding the molecular formula of an unknown compound from mass percent data. Placed the 1st step of the top of the list

- Assume that the sample contains 100.0 g of compound and express each mass percent as a mass in grams - Convert the mass of each element to moles of each element - Derive the empirical formula looking for the simplest whole number ratio of moles - Divide the molar mass of the compound by the mass of the empirical formula in order to find a multiple that is an integer - Subscript of the empirical formula by the integer multiple

Correctly order the steps necessary to calculate the empirical formula of a compound, assuming that the masses of each element of the compound are provided. Start with the 1st step at the top of the list

- Calculate the number of M o's of each element of the sample using mass/molar mass - Right the chemical formula containing fractional subscripts - Divide each subscript by the smaller subscript - If integers are not obtained, multiply each subscript by the smallest integer that gives all integer subscripts - verify that the integer subscripts cannot be divided by a common factor

Correctly ordered the steps necessary to determine the molecular formula for a compound using combustion analysis's data. Start with the 1st step at the top of the list

- Determine the masses of carbon and hydrogen from the masses of C02 and H20 - Determine the mass of oxygen, if present, by subtracting the masses of carbon and hydrogen from the total mass - Determine the number of moles of each element and the compound and hence the empirical formula - Determine the molecular formula using the empirical formula and the molar mass

Which of the following options identified the corrects coefficients required to balance the reaction illustrated? In the illustration, carbon is black and oxygen is red. select all that apply

- The reactant CO must have the coefficient 2 - CO2 is a product and has the coefficient 2

Correctly order the steps necessary to solve for the mass of a product, or 2nd reactant required, given the mass of one of the reactant in a chemical process. Start with the first step at the top of the list

- Write a balanced equation for the reaction - Convert the given mass into moles using molar mass. Convert moles of A to moles of B using a conversion factor derived from the balanced equation - Convert the most of the 2nd substance to mass using its molar math

Which of the following statements correctly describe the information conveyed by the balance equation 16Cu (s) + S8 (g)----> 8Cu2S(s)? Select all that apply

-16 moles of Cu react with 1 mole of S8 to form 8 moles of Cu2S - Cu and S8 are reactants and Cu2S is the product -16 atoms of Cu react with 1 molecule of S8 to form 8 formula units of Cu2S

1.52 x 10^24 atoms of Au corresponds to ________ mol of Au atoms. Report your answer to 3 significant figures, using decimal notation( Not scientific notation). Avogadros number is 6.022 x 10^23

2.52 mol