Ch 9 Section 3

Question 1

in the lab, a reaction is rarely carried out with exactly the required amount of

Answer 1

each o the reactants

Question 2

in many cases, one or more reactants is present in excess, meaning there is more than

Answer 2

the exact amount required to react

Question 3

once one of the reactants is used up, no more

Answer 3

product can be formed

Question 4

the substance that is completely used up first in a reaction is called the

Answer 4

limiting reactant

Question 5

the limiting reactant is the reactant that limits the amount of the other reactant that can

Answer 5

combine and the amount of product that can form in a chemical reaction

Question 6

the substance that is not used up completely is called the

Answer 6

excess reactant

Question 7

a limiting reactant may also be referred to as a

Answer 7

limiting reagent

Question 8

theoretical yield is the maximum amount of product that can be produced from

Answer 8

a given amount of reactant.

Question 9

in most chemical reactions, the amount of product obtained is less than the

Answer 9

theoretical yield

Question 10

reactants may contain impurities or may form

Answer 10

byproducts in competing side reactions

Question 11

in many reactions, all reactants are not converted to

Answer 11

products

Question 12

the measured amount of a product obtained from a reaction is called the

Answer 12

actual yield of that product

Question 13

chemists are usually interested in the

Answer 13

efficiency of a reaction

Question 14

the efficiency is expressed by comparing the

Answer 14

actual and theoretical yields

Question 15

the percentage yield is the ratio of the

Answer 15

actual yield to the theoretical yield, multiplied by 100