Question

3g of carbon is burnt completely In 8g of oxygen and 11g of carbon dioxide is
produced . What will be the mass of carbon dioxide formed when 9g of carbon burns in
50g of oxygen. How much amount of oxygen will be left unused.

Answer 1

Answer:

As per the given condition, when 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. Therefore, the law of conservation of mass is proved. Then, it also depicts that the carbon dioxide contains carbon and oxygen in a fixed ratio by mass, which is 3:8.

Answer 2

First, let us write the reaction taking place here

C + O2 → CO2

As per the given condition, when 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced.

3g + 8g →11 g ( from the above reaction)

Total mass of reactants = mass of carbon + mass of oxygen

=3g+8g

=11g

Total mass of reactants = Total mass of products

Therefore, the law of conservation of mass is proved.

Then, it also depicts that the carbon dioxide contains carbon and oxygen in a fixed ratio by mass, which is 3:8.

Thus it further proves the law of constant proportions.

3 g of carbon must also combine with 8 g of oxygen only.

This means that (50−8)=42g of oxygen will remain unreacted.

The remaining 42 g of oxygen will be left un-reactive. In this case also, only 11 g of carbon dioxide will be formed