Formula and equations (1) ✅

Question 1

what’s a compound

Answer 1

a substance made up of to or more different elements chemically joined together

Question 2

How do we write the formulae of compounds

Answer 2

Swap (valencies)
Drop
Cancel

Question 3

what are each of the periodic table groups valencies

Answer 3

group 1 valency = 1
group 2 = 2
group 3 = 3
group 4 = 4
group 5 = 3
group 6 = 2
group 7 = 1
group 8/0 = 0

Question 4

what is the formulae for Hydrochloric acid

Answer 4

HCl

Question 5

what is the formulae for nitric acid

Answer 5

HNo3

Question 6

what is the formulae for sulfuric acid

Answer 6

H2SO4

Question 7

what is the formulae for ethanoic acid

Answer 7

CH3COOH

Question 8

what is the formulae for water

Answer 8

H20

Question 9

what is the formulae for carbon dioxide

Answer 9

CO2

Question 10

what is the term relative atomic mass used for

Answer 10

elements

Question 11

what is the mass of carbon-12

Answer 11

12

Question 12

what do chemists compare the masses of the atom to

Answer 12

to the mass of a single atom of carbon-12

Question 13

what is Relative Atomic mass (Ar/RAM)

Answer 13

the mass number - top number

Question 14

what is relative formula mass used for (Mr/RFM)

Answer 14

compounds

Question 15

what is relative formula mass

Answer 15

the sum of the atomic mass of each atom in one molecule of a compound

Question 16

what is the relative formula mass of water?

Answer 16

water = H20
2 x H = 2x1
1 x O = 1x16
= 2 + 16
Mr = 18

Question 17

what is the Mr of potassium sulfate?
(relative formula mass)

Answer 17

Potassium sulfate = K2 SO4
2 x k = 2 x 39. }
1 x S = 1 x 32. } added together = 174
4 x O = 4 x 16 }

Question 18

what’s the mr (relative formula mass) of Iron (III) sulfate?

Answer 18

Iron(III)Sulfate = Fe2(SO4)3
2 x Fe = 2 x 56
3 x S = 3 x 32. }added = 400
12 x O = 12 x 16