Question

How many moles of hydrogen will be evolved when 6.50 g of zinc (Atomic weight = 65) is dipped in 6.023x102 molecules of hydrochloric acid at STP
(Zn + 2HCl → ZnCl, + H2) ​

Answer 1

Answer:

Given, Zinc react with HCl to form Zinc Chloride and Htdrogen gas at STP. A balanced chemical reaction is

Zn + 2HCl → ZnCl, + H2

Zn = 6.50 g

Mole of Zn = 6.50 / 65

= 0.1 mol

Hence , 6.50g Zn requires 2x6.023x10^22 molecules of HCl to react completely .

But we have used only 6.023x10^22 molecules of HCl. Hence , you can see that molecules of HCl are less than required for 6.5g Zn to react completely . So , the reaction will occur only until HCl is present .

So , now ,from above reaction ,

When 2*6 023*10^23 HCl is consumed , 1 mole of H2 is produced .

Hence , when 6.023*10^22 HCl is consumed , 0.05 mole of H2 will be produced .

Hope it will help .

By

Aaditya Singh