How many grams of hydrogen gas will be liberated when 6g of magnesium ribbon dissolves in 500cm3 of 6M HCl?
(Mg=24, H=1, Cl=35.5)
(Mg=24, H=1, Cl=35.5)
-
A.
1.2 g -
B.
0.7 g -
C.
0.5 g -
D.
0.3 g -
E.
0.12 g
Correct Answer: Option C
Explanation
Mg + 2HCl → MgCl2 + H2
6 molar contains 6 Χ 36.5 gms 1000 cc
Solution i.e 6 Χ 36.5/2gms in 500 cc
= 3 Χ 36.5
24 gms of mg will react with 2 Χ 36.5 HCl to liberate 2 gm of hydrogen
∴ 6 gms will liberate 6 Χ 2/24 Χ 1 = 0.5 gm of H2