Question

The following data were obtained when dinitrogen and dioxygen react together to form compounds:​

Answer 1

(a) when the mass of dinitrogen is 28g, mass of dioxygen combined is 32, 64, 32, and 80g. The corresponding ratio is 1:2:1:5. It is a simple whole number ratio. This illustrates the law of multiple proportions.

It states that, "if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element, are in the ratio of small whole numbers.

(b) (i) We know 1km=1000m

Or 1m = 1000 mm

Therefore 1km = 1000x 1000mm= 10^6 mm

1 km = 1 km x 1000m/1km x 1pm/10^-12 m

1 km = 10^15 pm

Hence, 1 km = 10^6 mm = 10^15 pm

(ii) We know 1kg = 1000mg

Or 1000mg= 1kg

Or 1mg= 1/1000 x 1= 0.01 kg

1 mg = 1 mg x 1g/1000mg x 1ng/10^-9 g

⇒ 1 mg = 10^6 ng

1 mg = 10^–6 kg = 10^6 ng

(iii) We know 1000 ml=l L

Or 1ml=1/1000 x 1= 0.01L

1 mL = 1 cm³ = 1 cm³

1dm x 1dm x 1dm/10cm x 10cm x 10cm

⇒ 1 mL = 10^–3 dm³

1 mL = 10^–3 L = 10^–3 dm³