Question

4 grams of a metal on heating with O2, gave 4.5 grams of the metal oxide. The equivalent weight of the metal is
1) 16 2) 8 3) 32 4) 64

Answer 1

Explanation:

The mass of metal oxide is 4g and that of oxygen is 1.6g.

Hence, the mass of metal=4g−1.6g=2.4g

Now Equivalent mass of oxygen=8g

Now,

Equivalent mass of oxygen

Equivalent mass of metal

=

mass of oxygen

mass of metal

Equivalent mass of metal=

1.6g

2.4g

×(8g)=12g

Therefore, equivalent mass of metal is 12g

Answer 2

Answer:

The equivalent mass of the metal is equal to 64g.

Therefore, the option (4) is correct.

Explanation:

Given:

The mass of metal oxide $=4.5g$

And, mass of metal, $m_{metal}=4g$

Mass of oxygen, $m_{oxygen}=4.5-4=0.5g$

Formation of metal oxide:   $M+ \frac{1}{2} O_{2}$  → $MO$

We can write it as $M^{2+}O^{2-}$

Therefore, n-factor for metal $=2$

The equivalent mass of a compound is equal to molar mass divided by n-factor of the compound.

Equivalent mass = Molar mass/ n-factor

Equivalent mass of oxygen,  $Eq_{(oxygen)}=\frac{16}{2} =8g$

$\frac{Eq_{(metal)}}{Eq_{(oxygen)}} =\frac{m_{metal}}{m_{oxygen}}$

$\frac{Eq_{(metal)}}{8} =\frac{4}{0.5}$

$Eq_{(metal)}=\frac{4}{0.5}*8$

Equivalent mass of metal = 64g