Chapter 3 - Stoichiometry

Question 1

chemical stoichometry

Answer 1

the calculation of the quantities of material consumed and produced in chemical reactions.

Question 2

mass spectrometer

Answer 2

an instrument used to determine the relative masses of atoms by the deflection of their ions on a magnetic field.

Question 3

mole

Answer 3

the number equal to the number of carbon atoms in exactly 12 grams of pure 12^C: Avogadro’s number. One mole represents 6.022x10^23 units.

Question 4

Avogadro’s number

Answer 4

the number of atoms in exactly 12 grams of pure 12^C, equal to 6.022x10^23 units.

Question 5

molar mass

Answer 5

the mass in grams of one mole of molecules or formula units of a substance; also called molecular weight.

Question 6

mass percent

Answer 6

the percent by mass of a component of a mixture or of a given element in a compound.

Question 7

empirical formula

Answer 7

the simplest whole-number ratio of atoms in a compound.

Question 8

chemical equation

Answer 8

a representation of a chemical reaction showing the relative numbers of reactant and product molecules.

Question 9

reactants

Answer 9

a starting substance in a chemical reaction. It appears to the left of the arrow in a chemical equation.

Question 10

products

Answer 10

a substance resulting from a chemical reaction. It is shown to the right of the arrow in a chemical equation

Question 11

mole ratio

Answer 11

the ratio of moles of one substance to moles of another substance in a balanced chemical equation.

Question 12

limiting reactant

Answer 12

the reactant that is completely consumed when a reaction is run to completion.

Question 13

theoretical yield

Answer 13

the maximum amount of a given product that can be formed when the limiting reactant is completely consumed.

Question 14

percent yield

Answer 14

the actual yield of a product as a percentage of the theoretical yield.