CHEMISTRY

Could you clarify 32,7 Zn? Is that supposed to be 32.7 kg?

I think the reaction is

Zn + 2HCl -> ZnCl2 + H2

For this, you will need two moles of HCl for each mole of Zn. The atomic weight of Zn is 65.4, H is 1.0 and Cl is 35.5. This means that for every 65.4 kg of Zn, you will need 73 kg of HCl (two times the sum of 1 and 35.5). Since your solution is 36% HCl, that means you need 202.7 kg of solution for every 65.4 kg of Zn. Conviently, half of 65.4 is 32.7, so instead of 202.7 kg, you need 101 kg of your HCl solution and some change.

CHEMISTRY
Hello!
If I` do this:

100/36*73=202,77

202,77-65,4
x -32,7

202,77*32,7=65,4* x

x=202,77*32,7/65,4=101kg
that is ok , but if I` do the same thing but the differente numbers
if there is 10% insted 36% and 10 g insted 32,7g and the formula , equation is the same

why is not correct???

100/10*72,9=729
729-65,4
x -10

the resault should be 405,8 but I` get 111,..
please help,again

I agree with you. I don't see how you could get 405.8 kg unless the reaction is incorrect.