1) 40

2) 44

3) 30

4) 160

5) 98

6) 180

7) 296

8) 101

9) 400

10) 187.5

11) 310

12) 107

**Questions**

There are quite a few questions here, so do not feel like you have to answer all of them.

1) Find the relative formula mass of MgO

The A_{r} of magnesium (Mg) is 24 and the A_{r} of oxygen (O) is 16.

2) Find the relative formula mass of CO_{2}

The A_{r} of carbon (C) is 12 and the A_{r} of oxygen (O) is 16.

3) Find the relative formula mass of C_{2}H_{6}

The A_{r} of carbon (C) is 12 and the A_{r} of hydrogen is (H) is 1.

4) Find the relative formula mass of Fe_{2}O_{3}

The A_{r} of iron (Fe) is 56 and the A_{r} of oxygen (O) is 16.

5) Find the relative formula mass of H_{2}SO_{4}

H = 1, S = 32, O = 16

6) Find the relative formula mass of C_{6}H_{12}O_{6}

O = 16, H = 1, C = 12

7) Find the relative formula mass of FeBr_{3}

Fe = 56, Br = 80

8) Find the relative formula mass of H_{2}SiCl_{2}

Cl = 35.5, Si = 28, H = 1

9) Find the relative formula mass of Fe_{2}(SO_{4})_{3}

Fe = 56, S = 32, O = 16

10) Find the relative formula mass of Cu(NO_{3})_{2}

Cu = 63.5, N = 14, O = 16

11) Find the relative formula mass of Ca_{3}(PO_{4})_{2}

O = 16, P = 31, Ca = 40

12) Find the relative formula mass of Fe(OH)_{3}

O = 16, Fe = 56, H = 1