Question

When 5g of Calcium is burnt in 2g of Oxygen then 7g of Calcium oxide is produced. What mass of calcium oxide will be produced when 5g of calcium reacts with 20g of oxygen?

(A) 7g

(B) 2g

(C) 25g

(D) 4g

Answer 1

(A)  correct answer is 7g

Explanation:

When 5g of calcium is burnt in 2g of oxygen ,we get 7g of calcium oxide  From this we understand that, calcium  and oxygen combine in the ratio 5:2.   

Hence when 5g of calcium is burnt in 20g of oxygen,it will produce only 7g of calcium oxide.  

This is in accordance with law of constant proportions.

Comments

Which law is ised