Question

How much MgO is obtained on heating 5 gm of $\left(MgC{O}_3\right)$ Magnesium carbonate?

• A. 2.4 gm
• B. 2.38 gm
• C. 2.8 gm
• D. 3.28 gm

Answer 1

Answer: (B)

2.38 gm

$MgC{O}_3\to MgO+C{O}_2$
Molecular weight of $MgC{O}_3$
= 24 + 12 +16 x 3 = 84
Molecular weight of MgO
= 24 + 16 = 40
On heating 84 gms of $MgC{O}_3$ the quantity of MgO obtained
= 40 gms
$\therefore$ On heating 5 gms of $MgC{O}_3$ the quantity of MgO obtained
$=\frac{40}{84}X5gms$
= 2.38 gms