Exam 1 ch 7

Question 1

Chemical change

Answer 1

Alters molecular composition

Question 2

Physical change

Answer 2

Alters state or appearance

Question 3

Chemical property

Answer 3

A property a substance displays only by changing composition

Question 4

Physical property

Answer 4

A property a substance displays without changing composition

Question 5

Chemical vs physical checklist

Answer 5

1. Is a new substance formed
2. Is it easily reversible
3. Are their signs (color/temp/burning)
4. Is the state changing
5. if yes chemical
6. if yes physical
7. if yes chemical
8. if yes physical

Question 6

Why do chemical equations must balance

Answer 6

-Law of conservation of mass
-Mass cannot be created or destroyed

Question 7

Limiting reactant

Answer 7

Reactant that limits the amount of product you can make

Question 8

Theoretical yield

Answer 8

Amount of product that can be made with the limiting reactant

Question 9

Actual yield

Answer 9

Actual amount of product produced

Question 10

Percent yield

Answer 10

-Percent of actual product produced.

-Actual/Theoretical * 100

Question 11

Excess reactant

Answer 11

-Remaining product after finding limiting
-LR mol * ER mol equation/ LR mol equation = Used ER

OG ER- Used ER