Chapter 7 Review

Percent Comp

100

What is the percent by mass of carbon in C₂H₅OH?

52.1%C

200

What is the percent by mass of oxygen in Al₂(CO₃)₃

61.54% Oxygen

300

Calculate the mass percent of EACH element in the MgC0₃, magnesium carbonate. 

28.9% Mg

14.3% C

56.9% O

400

Calculate the mass percent of EACH element in CH₃CH₂CH₂CH₂CH₂C0₂H, caproic acid, an organic acid with a characteristic goat odor.

62.0% C

10.4% H

27.6% O

500

The weight percent of hydrogen in a compound with a formula, EH₃, is 8.9%. 

What is the atomic weight and probable identity of E?

30.9 g/mol Phosphorous

Emp/Molec Formula

100

Give the empirical formula that corresponds to terephthalic acid, C₈H₆0_4.

C₄H₃O₂

200

A compound with the empirical formula CH₂ was found to have a molar mass of approximately 84 g/mol. What is the molecular formula of the compound?

C₆H₁₂

300

If 10.00 grams of copper metal is heated strongly in the air, the sample gains 2.52 grams of oxygen in forming an oxide. Determine the empirical formula of the oxide. 

CuO

400

A compound consists of 65.45% C, 5.492% H, and 29.06% O on a mass basis and has a molar mass of approximately 110 g/mol. Determine the molecular formula. 

C₆H₆O₂

500

Transition metals can combine with carbon monoxide (CO) to form compounds such as Fe(CO)₅ and Co(CO)₈. Assume that you combine 0.125 grams of nickel with CO and isolate 0.364 grams 

What is the value of x? 

Ni(CO)₄

Formula Mass/Atomic Mass, Molar Mass

100

Calculate the molar mass of sodium nitride, Na₃N.

82.976g/mol

200

Calculate the formula mass of magnesium sulfate.

120.37g/mol

300

Calculate the molar mass of copper (ll) nitrate.

187.6 g/mol

400

3.00 moles of an unknown element has a mass of 106.36 grams. What is the average atomic mass of the element and what is its identity?

35.453 g/mol, Chlorine

Mass/Moles/Atoms Calculations

100

Calculate the number of moles of calcium that contains the same number of moles as 2.00 moles of zinc.

2 moles of Calcium

200

Calculate the mass, in grams, of one molecule of the naturally occurring acid, oxalic acid.

1.50x10^-22g

300

Calculate the number of moles contained in 8.76 grams of strontium fluoride.

0.0697 mole

400

Calculate the number of grams of iron that contain the same number of atoms as 2.24 grams öf cobalt. 

2.12g Fe

500

Calculate the number of sulfur atoms present in 2.01 grams of sodium thiosulfate, Na₂S₂0₃.

1.53x10²² atoms of S

Naming

100

What is the chemical formula of dintrogen monoxide?

N₂O

200

What is the name of NiCO₃

Nickel(II)carbonate

300

What is the chemical formula of calcium chloride?

CaCl₂

400

Name HBr

Hydrobromic acid

500

What is the formula for sulfurous acid?

H₂SO₃