Mole to Mole and Mole to Mass Problems

Carbon tetrachloride is a solvent which is used as a refrigerant and also as a cleaning agent. Today, methane and chlorine are mainly used to produce carbon tetrachloride:

CH₄ + 4Cl₂ → CCl₄ + 4HCl

How many grams of carbon tetrachloride can be produced from reacting 5.5 moles of of chlorine (Cl₂) with excess methane?

• 154 g

• 847 g

• 212 g

• 4 g

In the reaction 2RbNO₃ → 2RbNO₂ + O₂, how many moles of O₂ are produced when 5.0 mol of RbNO₃ decompose?

• 1.0 mol

• 2.5 mol

• 3.0 mol

• 7.5 mol

Tags

NGSS.HS-PS1-7

In 1860, Robert Boyle was the first to use phosphorus to ignite sulfur-tipped wooden splints that gave rise to our modern matches. One of the ways it can be made involves the chemical reaction of calcium phosphate with carbon and silicon dioxide in a furnace:

2Ca₃ (PO₄ )₂ + 6SiO₂ + 10C → 6CaSiO₃ + P₄ + 10CO

Refer to the information above. If you use 2.25 moles of calcium phosphate and an excess of silicon dioxide and carbon, how many moles of phosphorus will be produced?

• 1.125 moles

• 4.5 moles

• 31 moles

• 34.9 moles

Baking soda (sodium bicarbonate) is a compound commonly used in baked goods, as a deodorizer in refrigerators, and as an antacid. Commercial quantities of baking soda are produced by mixing soda ash dissolved in water with carbon dioxide. Baking soda precipitates as a solid from this method:

Na₂CO₃ + CO₂ + H₂O → 2NaHCO₃

If you have 25 moles of soda ash, how many grams of sodium bicarbonate can you produce?

• 84 grams

• 4200 grams

• 50 grams

• 1050 grams

One step in the production of copper is to heat copper (I) sulfide, Cu₂S, with oxygen. This produces copper (I) oxide and sulfur dioxide gas according to the following reaction:

2Cu₂S_(s) + 3O_2(g)→ 2Cu₂O_(s) + 2SO_2(g)

Which is the greatest mass of SO₂ that can be produced from 15.0 mol Cu₂S?

• 480 g SO₂

• 721 g SO₂

• 961 g SO₂

• 1920 g SO₂