Question

When 1 gram of a mixture of aluminium and zinc was treated with HCl, a gas was liberated. At the end of the
reaction, the volume of the liberated gas was found to be 524 cm3
, under STP conditions. The individual
weights of aluminium and zinc in the mixture, respectively, are:

Answer 1

Let Al be= xg

and Zn= 1-xg

Then the balanced reaction become

$Al+3CHl-> Al+Cl3+3/2H2$

Then number of moles become

$Al+3CHl= Al+Cl3+3/2H2$

$\frac{x}{27}$  =$\frac{3}{2}$×$\frac{x}{27}$=$\frac{x}{18}$ moles

Similarly in the reaction

$Zn+2HCl->ZnCl2_{123} +H_{2}$

$\frac{1-x}{65.3}$               $\frac{1-x}{65.3}$

The total Hydrogen produced = $\frac{x}{18}$ + $\frac{1-x}{65.3}$ = $\frac{524}{22400}$

Solving we get

x=0.21g and Zn= 0.79g

Hence answer is

0.2g and 0.8g