Unit 3 Review

Definitions

100

The sum of the atomic masses of the atoms in a formula

What is Molar Mass? 

200

A conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction

What is mole ratio?

300

The reactant that determines the amounts of the other reactants that can combine and the amount of product that can form in a chemical reaction.

What is the limiting reactant?

400

The ratio of the actual yield to the theoretical yield, multiplied by 100.

What is percent yield?

500

The elements in a chemical compound are always present in the same proportions by mass

What is Law of Definite Proportions

Mol Ratios/LR

100

2Mg +O2 --> 2MgO How many moles of magnesium oxide are produced from 1.2 moles of magnesium?

What is 1.2 mol MgO?

200

Ammonia, NH3, is widely used as a fertilizer and in many household cleaners. How many moles of ammonia are produced when 6 mol of hydrogen gas react with an excess of nitrogen gas?

What is 4 mol NH3?

300

Hydrogen and oxygen gases react under a specific set of conditions to produce water. How many moles of oxygen would be required to produce 5.0 moles of water?

What is 2.5 mol O₂?

400

 Consider the reaction I₂O₅(g) + 5 CO(g) -------> 5 CO₂(g) + I₂(g). 

If 80.0 grams of iodine(V) oxide reacts with 28.0 grams of carbon monoxide, determine the mass of iodine which could be produced

What is 50.8g I₂? 

500

Aluminum oxide reacts with iron to form Fe₃O₄ and Aluminum. Determine the limiting reactant when 5 moles of aluminum oxide reacts with 7 moles of iron.

What is iron?

Mass to Mass

100

Mg + 2HCl --> MgCl₂ + H2 What mass of hydrogen is produced from the reaction of 75 g HCl (MM=36.5 g/mol) and excess Mg?

What is 2.0 g H₂?

200

2KClO₃ --> 2KCl + 3O₂ How many grams of KCl are produced if 5.0 g of KClO₃ is decomposed?

What is 3 g KCl?

300

Sodium and chlorine react to produce sodium chloride (table salt; MM=58.5 g/mol). Determine the amount of product that can be produced from 24.7 g of sodium and excess chlorine.

What is 62 g NaCl?

400

Sodium hydroxide reacts with sulfuric acid (H₂SO₄; MM=98.1 g/mol) to form water and sodium sulfate. How many grams of sodium sulfate (MM=124 g/mol) will be formed from 200 g NaOH (MM=40 g/mol) and an excess of sulfuric acid?

What is 355 g Na₂SO₄?

500

When copper (II) chloride reacts with sodium nitrate, copper (II) nitrate and sodium chloride are formed. If 15 g CuCl₂ (MM=134.5 g/mol) react with 20 g NaNO₃ (MM=85 g/mol), how much sodium chloride (MM = 58.5 g/mol) can be formed?

What is 13.0 g NaCl?

Miscellaneous

100

N₂ + 3H₂ --> 2NH₃ In the reaction above, a student reacted 28 g of nitrogen with an excess of hydrogen. According to the students measurements, the reaction produced 30 g of product. The theoretical yield was 34 g. What is the student's percent yield?

What is 88%?

200

Avogadro's number.

What is 6.02 x 10²³?

300

How many grams are there in 4.5 x 10²² formula units of Ba(NO₂)₂? 

What is 17.1 g? 

400

A hydrate is determined to be 45.53% water and 54.57% CoCl₂. Find the chemical formula for the hydrate. 

What is CoCl₂ - 6H₂O

500

A hydrate of magnesium sulfate has a mass of 13.52 g. The sample is heated until no water remains. The MgSO₄ anhydrate has a mass of 6.60 g. Find the formula of the hydrate. 

What is MgSO₄ . 7H₂O