Question

The percentage by mass of chlorine in the chloride of a metal is $80\%$. $33.375g$ of this chloride on vaporization occupies a volume of $5.6$ litre at STP. Now select the correct options:

• A. Valency of the metal is 2
• B. Molecular weight of the metal chloride is $133.5u$
• C. Atomic weight of the metal is $27g$
• D. $9g$ of the metal can completely react with $8g$ of oxygen

Answer 1

Answer: (B), (C), (D)

The correct options are
B Molecular weight of the metal chloride is $133.5u$
C Atomic weight of the metal is $27g$
D $9g$ of the metal can completely react with $8g$ of oxygen

Since 5.6 litre will be occupied by $\frac{1}{4}$ mole of NTP, so the molecular weight of metal chloride
=$33.375\times 4=133.5g$

Let, the formula of the chloride be $MC{l}_x$
x $\times$ mole of metal = $1\times$ mole of Cl
Let the total mass of metal chloride = 100 g
Then mass of Cl = 80 g
& mass of metal = 20 g
& let molecular weight of metal$=M_A$
$x\times \frac{20}{M_A}=1\times \frac{80}{35.5}Also,M_A+35.5x=133.5$
On solving, x = 3 & $M_A=27g$
Equivalent mass of the metal = 9 g
Hence, 9 g of the metal can combine with 8 g oxygen.