Honors Chemistry Midterm Review

Balancing Equations

100

___ Mg + ___ HCl → ___ MgCl₂ + ___ H₂

Mg + 2 HCl → MgCl₂ + H₂

200

___ Al + ___ CuCl₂ → ___ AlCl₃ + ___ Cu

2 Al + 3 CuCl₂ → 2 AlCl₃ + 3 Cu

300

___ Na₃PO₄ + ___ MgCl₂ → ___ NaCl + ___ Mg₃(PO₄)₂

2 Na₃PO₄ + 3 MgCl₂ → 6 NaCl + Mg₃(PO₄)₂

400

___ Fe₂(SO₄)₃ + ___ KOH → ___ K₂SO₄ + ___ Fe(OH)₃  

Fe₂(SO₄)₃ + 6 KOH → 3 K₂SO₄ + 2 Fe(OH)₃  

500

___ C₄H₁₀ + ___ O₂ → ___ CO₂ + ___ H₂O

2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O

Naming Formulas

100

Name for NaCl

Sodium Chloride

200

Formula for Calcium Nitrate

Ca(NO₃)₂

300

Name for FeCl₃

iron(III) chloride

400

Formula for ammonium sulfate

(NH₄)₂SO₄

500

Name for HClO₃ 

Chloric acid

Emphirical/Molecular Formulas

100

A compound contains 2 moles of carbon and 4 moles of hydrogen. What is the empirical formula?

CH₂

200

What is the empirical formula of a compound containing 40% carbon, 6.7% hydrogen, and 53.3% oxygen?

CH₂O

300

The empirical formula is CH₂O, and the molar mass of the molecular formula is 180 g/mol. What is the molecular formula?

C₆H₁₂O₆

400

A compound is 85.7% C and 14.3% H with a molar mass of 84 g/mol. What is the molecular formula?

C₆H₁₂

500

A compound contains 72.0% carbon and 12.0% hydrogen. The rest is oxygen. A 90.0 g sample of the compound contains 0.50 moles. What is the molecular formula?

C₉H₁₈O₂

Limiting/excess reactants

100

If Hydrogen reacts with Oxygen to produce water, and you have 4 moles of H₂ and 2 moles O₂, which is the limiting reactant?

H₂

200

For the reaction: N₂ + 3 H₂ → 2 NH₃, you have 5 moles N₂ and 12 moles H₂. How many moles of NH₃ can form?

8 moles

300

2 H₂ + O₂ → 2 H₂O, you have 5 moles H₂ and 2 moles O₂.

• Identify the limiting reactant.

• How many moles of H₂O are produced?

Limiting reactant: O₂, H₂O produced: 4 moles, H₂ remaining: 1 mole

400

For the reaction: N₂ + 3 H₂ → 2 NH₃, you have 6 moles N₂ and 14 moles H₂.

• Determine the limiting reactant.

• Calculate the moles of NH₃ produced.

• How many moles of excess reactant remain?

Limiting reactant: H₂, NH₃ produced: 9.33 moles, N₂ remaining: 2.67 moles

500

Aluminum reacts with chlorine to produce aluminum chloride. You have 5 moles Al and 7 moles Cl₂.

• Identify the limiting reactant.

• How many moles of aluminum chloride are formed?

• How many moles of the excess reactant remain?

Limiting reactant: Al, AlCl₃ produced: 5 moles, Cl₂ remaining: 3.5 moles

Molarity Problems

100

You dissolve 10 g of NaOH in 500 mL of water. What is the molarity?

0.5 M

200

You dissolve 8.5 g of KOH in 250 mL of water. What is the molarity of the solution?

0.61 M

300

A 0.75 L solution of H₂SO₄ contains 60 g H₂SO₄. What is the molarity?

0.82M

400

You have 0.50 L of 2 M NaOH that reacts with HCl. If the HCl solution is 1.5M, what volume of HCl is required?

0.67 L

500

You have 0.25 L of 3 M H₂SO₄ reacting with NaOH. If the NaOH solution is 2M, what volume of NaOH is required?

0.75 L