2.1.2 Compounds, Formulae And Equations

Question 1

What ions are formed by group 1? What happens to the electrons?

Answer 1

1+ (lose electron)

Question 2

What ions are formed by group 1? What happens to the electrons?

Answer 2

1+ (lose electron)

Question 3

What ions are formed by group 2? What happens to the electrons?

Answer 3

2+ (lose 2 electrons)

Question 4

What ions are formed by group 3? What happens to the electrons?

Answer 4

3+ (lose 3 electrons)

Question 5

What ions are formed by group 5? What happens to the electrons?

Answer 5

3- (gain 3 electrons)

Question 6

What ions are formed by group 6? What happens to the electrons?

Answer 6

2- (gain 2 electrons)

Question 7

What ions are formed by group 7? What happens to the electrons?

Answer 7

1- (gain an electron)

Question 8

What is a binary compound?

Answer 8

A compound that only contains two elements.

Question 9

How do you name a binary compound?

Answer 9

First element - keep same
Second element - change ending to -ide

Question 10

What is a polyatomic ion?

Answer 10

An ion that contains atoms of more than one element bonded together.

Question 11

Ammonium ion

Answer 11

(NH4)+

Question 12

Hydroxide ion

Answer 12

(OH)-

Question 13

Nitrate ion

Answer 13

(NO3) -

Question 14

Carbonate ion

Answer 14

(CO3) 2-

Question 15

Sulfate ion

Answer 15

(SO4) 2-

Question 16

Silver ion

Answer 16

(Ag) +

Question 17

Zinc ion

Answer 17

(Zn) 2+

Question 18

Zinc ion

Answer 18

Zn (2+)

Question 19

How do you write formulae?

Answer 19

Make each ions charges equal, to the other in the compound (swap, drop and cancel.)

Question 20

What is empirical formulae?

Answer 20

The simplest whole number ratio of the number of atoms of each element in a compound.

Question 21

How do you find empirical formulae?

Answer 21

Assume percentages are grams.
Find moles.
Divide by smallest number to get ratio.
Use ratio to write formulae.

Question 22

Why do we use empirical formulae ?

Answer 22

Empirical formulae will always be the same, even as the size of crystals vary. (Unlike the molecular formula)

Question 23

What is molecular formulae ?

Answer 23

The number of atoms of each element in a compound.

Question 24

How do you find the molecular formula?

Answer 24

Find empirical formula.
Divide molar mass given by molar mass of empirical formulae.
Use this answer to multiply the empirical formula.