Chem11

Question 1

Define gram equivalent mass

Answer 1

Mass that gains/loses 1 mole electrons in reaction

Question 2

Calculate equivalent mass of Al³⁺ (Al=27)

Answer 2

27/3 = 9 g

Question 3

Calculate equivalent mass of Cu²⁺ (Cu=63.5)

Answer 3

63.5/2 = 31.75 g

Question 4

Why is Ag’s equivalent mass equal to its atomic mass?

Answer 4

Because Ag⁺ has +1 charge (108/1 = 108)

Question 5

Find equivalent mass of Fe in FeCl₂

Answer 5

Fe²⁺ → 56/2 = 28 g

Question 6

Find equivalent mass of Fe in FeCl₃

Answer 6

Fe³⁺ → 56/3 = 18.67 g

Question 7

How to determine ion charge from compound name?

Answer 7

E.g., iron(III) chloride → Fe³⁺

Question 8

How to determine ion charge from formula?

Answer 8

E.g., Fe₂O₃ → 2Fe³⁺ (balance with O²⁻)

Question 9

How to determine ion charge from equation?

Answer 9

From electron count (Fe³⁺ + 3e⁻ → Fe)

Question 10

Why do some elements have multiple equivalent masses?

Answer 10

Different oxidation states (e.g., Fe²⁺ vs Fe³⁺)

Question 11

What is the equivalent mass of O²⁻? (O=16)

Answer 11

16/2 = 8 g

gains 2e⁻ → O²⁻

Question 12

What is the equivalent mass of H⁺? (H=1)

Answer 12

1/1 = 1 g

H⁺ + e⁻ → H