Question

when
Mg reacts with
HCl, MgCl2
and H2 gas is
formed.
For producing 1g hydrogen , how
much
mag hesium is needed?
​

Answer 1

Answer:

Explanation:

$Mg + HCl --> MgCl_{2} + H_{2}$

Balancing the equation, we get

$Mg + 2HCl --> MgCl_{2} + H_{2}$

1 mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole each of magnesium chloride and hydrogen gas.

Now, number of moles in 1 g of hydrogen

= 1/molar mass of H₂

= 1/2 = 0.5 mol

∴ Required number of moles of magnesium is also 0.5.

Required mass of magnesium

= (molar mass of magnesium × 0.5) g

= (24 × 0.5) g

= 12 g