chem101chapter8

Balancing Equations

100

Balance the following equation: 

_ FeO + _ PdF₂ → _ FeF₂ + _ PdO 

1 FeO + 1 PdF₂ → 1 FeF₂ + 1 PdO 

Already balanced

200

Balance the following:

_ Al + _ O2  → _ Al2O3

4 Al + 3 O2  → 2 Al2O3

300

Balance the following: 

_ HClO₄ + _ P₄O₁₀ → _ H₃PO₄ + _ Cl₂O₇ 

12 HClO₄ + P₄O₁₀ → 4 H₃PO₄ + 6 Cl₂O₇

400

Balance the following:

_ PCl5 + _ H2O  → _H3PO4 + _ HCl

PCl5 + 4 H2O  → H3PO4 + 5 HCl

500

Balance the following: 

_ Cu + _ HNO3 → _ Cu(NO3)2 + _ NO + _ H2O 

3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2 NO + 4 H2O 

Molar Mass

100

What is the molar mass of oxygen?

15.999g

200

What is the molar mass of CO₂?

44.01g

300

What is the molar mass of sodium hydroxide?

39.997g/mol

400

What is the molar mass of HSO4?

97.064 g/mol

500

What is the molar mass of Pb(Cr2O7)2?

639.2g/mol

Problem Solving problems

100

Determine the number atoms of 65.38 grams of Zinc.

6.022*10²³ atoms

200

How many moles are in 1.2*10³ grams of ammonia, NH3?

70.5 moles

300

How many atoms are there in 122 grams of Cu(NO3)2?

3.92*10²³ atoms Cu(NO3)2

400

How many grams are there in 7.5*10²³ atoms of H₂SO₄?

122.19 grams

500

How many atoms of Oxygen are present in 25 grams of CO? 

5.37*10²³atomsO

Percent composition

100

What is the formula for percent composition?

part/whole

200

What is the percent composition of carbon in C₁₆H₁₅O₄?

C: 70.83%

300

What is the percent composition of each element in HCl?

H: 3%

Cl: 97%

400

What is the percent composition of copper (II) bromide?

Cu: 28.45%

Br: 71.55%

500

What is the percent composition of each element in (NH₄)₃PO₄?

N: 28%

H: 8%

O: 43%

P: 21%

Empirical/Molecular Formula

100

What is the difference between empirical and molecular formula?

• Empirical formula: simplest whole number ratio 

• Molecular formula: (empirical)n 

200

An oxide of chromium is found to have the following % compositions: 68.4% Cr and 31.6% O. Determine empirical formula.

Empirical: Cr2O3

300

The molar mass of nicotine is 162.1g/mol. It contains 74% of Carbon, 8.7% of Hydrogen, and 17.3% of Nitrogen. Determine the empirical formula and then using the empirical, find the molecular formula.  

Empirical Formula: C5H7N

Molecular Formula: C10H14N2

400

A compound with 5.9265% H and 94.0735% O has a molar mass of 34.01468 g/mol. Determine the empirical and molecular formula of this compound

E: HO

M: H2O2

500

The composition of Phenyl magnesium bromide contains 39.7458% of Carbon, 2.77956% of Hydrogen, 13.4050% of Magnesium, and 44.0697% of Bromide. The molar mass is 181.313g/mol. Determine the empirical formula, and then using the empirical formula, what is the molecular formula?

E: C6H5MgBr

M: C6H5MgBr