Mastering Stoichiometry Concepts

What is a mole in chemistry?

• A mole is a measure of temperature in chemistry.

• A mole is a unit that represents 6.022 x 10^23 particles of a substance.

• A mole is a type of chemical reaction.

• A mole is a unit of mass equivalent to one gram.

How many molecules are in 2 moles of water?

• 1.2044 x 10^24

• 6.022 x 10^23

• 3.6888 x 10^24

• 1.2044 x 10^22

Balance the equation: H2 + O2 → H2O.

• H2 + O2 → H2O

• H2 + O2 → H2 + O

• 2 H2 + 2 O2 → 2 H2O

• 2 H2 + O2 → 2 H2O

What is the limiting reactant in the reaction: 2H2 + O2 → 2H2O if you have 3 moles of H2 and 1 mole of O2?

• H2O

• O2

• 2H2

• H2

Calculate the percent yield if 5 grams of product were obtained from a theoretical yield of 10 grams.

• 50%

• 25%

• 100%

• 75%

If 4 moles of A react with 3 moles of B, how many moles of C are produced in the reaction A + B → C?

• 2 moles of C

• 3 moles of C

• 1 mole of C

• 4 moles of C

What is the molar mass of NaCl?

• 62.45 g/mol

• 56.12 g/mol

• 60.00 g/mol

• 58.44 g/mol

How do you determine the excess reactant in a chemical reaction?

• The reactant that remains after the reaction is complete.

• The reactant that is completely consumed during the reaction.

• The reactant that is added in excess to speed up the reaction.

• The reactant that is present in the smallest amount before the reaction.

If 10 grams of Na reacts with Cl2 to produce NaCl, what is the theoretical yield of NaCl?

• 20 grams

• 30 grams

• 15 grams

• 25.5 grams

What is the mole ratio of reactants in the balanced equation: 2H2 + O2 → 2H2O?

• 1:1

• 2:1

• 2:3

• 1:2