Question

40g of metal reacts with 16g of oxygen gas.calculate no. of equivalance of metal.

Answer 1

40g of metal reacts with 16g of oxygen

Atomic mass of oxygen = 16

oxidation number of oxygen = 2

Equivalent mass of oxygen = 16/2 = 8

So, equivalents of oxygen in 16g O2 = 16/8 = 2
______________________

Number of equivalents of metal = number of equivalents of oxygen = 2

So 2 equivalents of metal = 40g

Equivalent weight of metal = 40/2 = 20g
______________________

Thus, equivalence of metal is 20g.

Answer 2

Given,  

Equivalent weight of  oxygen = 16/2 = 8

16 gram of  oxygen reacts  with 40g of  metal

1 gram of  oxygen reacts  with 40/16g of  metal

8 gram of  oxygen reacts  with (40/16)*8= 20 g of  metal  

We know that, the mass of element  that reacts with 8 gram of  oxygen is the equivalent  mass of  that metal or  element

Hence,

equivalent  mass of  metal = 20 g