Zn + 2HCl ---> ZnCl2 + H2(g)
What mass of zinc is needed to produce 115 mL of hydrogen?
t's given 115 mL of hydrogen, so can convert to 115/1000/22,4 = 0.0051 moles H2
- the ratio between HCl and H2 is 2 : 1, so the moles of HCl needed for this reaction is 0.01
- the ratio between Zn and H2 is 1 : 1, so the moles of Zn needed for this reaction is 0.0051
so the mass of Zn need is 0.0051*65 = 0.3315 (g)
How many moles of HCl are needed for the reaction? (5 marks)
6 answers
confused by moles part
moles HCl needed = 2 x 0.0051 since stoichiometric ratio is 2:1
moles HCl = 0.01 moles
moles HCl = 0.01 moles
You are correct in saying that
the ratio between HCl and H2 is 2 : 1, so the moles of HCl needed for this reaction is 0.01
the ratio between HCl and H2 is 2 : 1, so the moles of HCl needed for this reaction is 0.01
yes if at Standard temp and pressure, 22.4 liters/mol
so
0.115 liters / 22.4 = 0.00513 mols of H2 and of Zn
so yes 0.00513 mols * 65.4 grams/mol = 0.336 grams of zinc
close enough we agree
Now for every mol of H2 you need 2 mols of HCl so we agree again
2 * 0.00513 = 0.01 mols HCl
so
0.115 liters / 22.4 = 0.00513 mols of H2 and of Zn
so yes 0.00513 mols * 65.4 grams/mol = 0.336 grams of zinc
close enough we agree
Now for every mol of H2 you need 2 mols of HCl so we agree again
2 * 0.00513 = 0.01 mols HCl
this curriculum has been used for a few years and all the answers are online XD
yup lol i've seen some of the exact same questions online from posts that are 9 yrs ago, think it goes further back if I recall based on some others haha.
1 answer