Question

when 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced . what mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen?​?

please help me​

Answer 1

Method (1) :-

The mass ratio of C and O in compound CO₂ is :-

= 12 : 16×2

= 12 : 32

= 3 : 8

According to Law of Constant Proportions, 3g of Carbon will always combine with 8g of Oxygen to form carbon dioxide. In this case, mass of oxygen is given as 50g which is excess. So, (50 - 8) = 42g of oxygen will remain unreacted.

Thus, mass of CO₂ formed is :-

= 3g + 8g

= 11g

Method (2) :-

The balanced chemical equation for the reaction is :-

C + O₂ → CO₂

Moles of C :-

= Given Mass/Molar mass

= 3/12

= 0.25 mole

Moles of O₂ :-

= Given Mass/Molar mass

= 50/32

= 1.5625 mole

Here, we are given with mole moles of O₂ than C. Thus Carbon is the limiting reagent, and will control the amount of product.

Now, from the equation :-

∵ 12g of C → 44g of CO₂

∴ 3g of C → 3×44/12 = 11g of CO₂

Hence, mass of CO₂ formed is 11g.