Chapter 7: Textbook

Question 1

Why is the flame visible in a combustion reaction?

Answer 1

This happens when the carbon atom has broken free from the wax molecule but has not yet combines with oxygen

Question 2

What does a chemical reaction not tell us?

Answer 2

• The pressure and temperature
• What happens in between the beginning and the end
• The quantities

Question 3

What are the 2 assumptions we make about reactants?

Answer 3

• Reactions are spontaneous

- Reactions are fast

Question 4

What are two descriptions of reactions?

Answer 4

• Reactions are quantitative

- Reactions are stoichiometric

Question 5

What does it mean when a reaction is quantitative?

Answer 5

-A reaction is more 99% complete meaning one reactant is 100 percent used up

Question 6

What does is mean by reactions are stoichiometric?

Answer 6

This means that there is a simple whole number ratio of chemical amounts

Question 7

When is collision theory only useful?

Answer 7

When the reactants are dissolved in a solution because many reactions will only happen when in a solution

Question 8

What is a drawback to doing reactions in a solution?

Answer 8

It is difficult to tell the reactant and products from the solvent

Question 9

What are the steps to writing a net ionic equation?

Answer 9

1: Write a reaction
2: Balance it
3: Separate the aqueous ones into separate ions with the balances
4: Eliminate the ones that remain the same

Question 10

What are spectator ions?

Answer 10

Ions that are present but do not take part in or change during a reaction

Question 11

What is a limiting reagent?

Answer 11

The reactant whose entities are completely consumed in a reaction. Meaning the reaction stops when when all the reactant is used up

Question 12

What is an excess reagent?

Answer 12

The reactant who entities are present in surplus amounts so that some remains after the reaction ends

Question 13

What is stoichiometry?

Answer 13

The relative quantities of the reactions and products by chemical amount (in moles)

Question 14

What is Gravimetric Stoichiometry?

Answer 14

The procedure for calculating the masses of reactants in a chemical reaction

Question 15

What is percent yield?

Answer 15

The ratio of actual or experimental quantity of product obtained (actual yield) to the theoretical quantity of product (predicted yield) obtained from a stoichiometry calculation

Question 16

What is the formula for percent yield?

Answer 16

Actual yield/Predicted yield x 100

Question 17

What are some common sources of experimental uncertainty?

Answer 17

• All measurements

- The purity of a chemical used

Question 18

What is gas stoichiometry?

Answer 18

The method of predicting or analyzing the quantity of gas involved in a chemical reactions

Question 19

What is solution stoichiometry?

Answer 19

The applications of stoichiometric calculation principles to substances in a solution