question_answer 75)

  Hydrogen gas is prepared in the laboratory by reacting dilute HCl with granulated zinc. Following reaction takes place : \[Zn+2HCl\to ZnC{{l}_{2}}+{{H}_{2}}\] Calculate the volume of hydrogen gas liberated at STP, when 32.65 g of zinc reacts with HCl. 1 mol of a gas occupies 22.7 L volume at STP; atomic mass of \[Zn=65.3\,u\].

Answer:

  \[\underset{\underset{65.3g}{\mathop{1\,mol}}\,}{\mathop{Zn}}\,+2HCl\to ZnC{{l}_{2}}+\underset{\underset{22.7L\,at\,STP}{\mathop{1\,mol}}\,}{\mathop{{{H}_{2}}}}\,\] Volume of \[{{H}_{2}}\] gas liberated by 32.65 g Zinc a \[\frac{22.7}{65.3}\times 32.65\] \[=11.35L\]at STP