Question

30 gm of Mg and 30 gm of O₂ are reacted and the residual mixture contains ... 

(a)   60 gm of MgO only

(b)   40 gm of MgO and 20 gm of O₂ 

(c)   45 gm of MgO and 15 gm of O₂ 

(d)   50 gm of MgO and 10 gm of O₂

Answer 1

Correct option  (d) 50 gm of MgO and 10 gm of O₂

Explanation:

2 x 24 gm 32 gm    2 x40 gm

Here, 48 gm of Mg requires 32 gm of O₂ to form 80 gm MgO 

so, 30 gm of Mg requires 20 gm of O₂ to form 50 gm MgO 

so, 10 gm of O₂ is remain.