Chemistry Extra Point

Balance the following equations:

Cu + HBr --> CuBr₂ + H₂

• Cu + HBr --> CuBr₂ + H₂

• Cu + 2HBr --> CuBr₂ + H₂

• 2Cu + 2HBr --> 2CuBr₂ + H₂

• Cu + 4HBr --> CuBr₂ + 2H₂

Calculate the relative formula masses (Mr) of CH₄

(Ar C=12 ; H=1)

• 18

• 17

• 16

• 14

Calculate Mr of H₂CO₃

(Ar H=1 ; C=12 ; O=16)

• 62

• 64

• 60

• 58

Calculate the relative formula masses of KNO₃

(Ar K = 39 ; N = 14 ; O = 16)

• 99

• 100

• 101

• 102

calculate mass of 1 mol of SO₂.

(Mr SO₂ = 64 g/mol)

• 32

• 64

• 68

• 96

Mr is relative ..... masses

calculate the mass of 0.5 mol of Na₂O

(Mr Na₂O = 62 g/mol)

• 62 g

• 50 g

• 46 g

• 31 g

calculate the number of moles of 1 g of HF.

(Mr HF = 20 g/mol)

• 0.05 mol

• 0.5 mol

• 0.01 mol

• 0.1 mol

calculate moles of 17kg of NH₃.

(Mr NH₃ = 17 g/mol)

• 1 mol

• 10 mol

• 100 mol

• 1000 mol

In chemical equation, there are 4 states of matter, including solid, gas, liquid and ... solution