Question

20ml of 0.1m of H2SO4 is mixed with 30ml of 0.1m of NaOH. Find the molarity of H+ ions in the solution.

Answer 1

the molarity is 1/50

Answer 2

Answer:

The molarity of $H^+$ ions in the solution is 0.02 M.

Explanation:

$2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O$

Moles of sulfuric acid in 20 ml of 0.1 M solution.

$0.1 M=\frac{Moles}{0.02 L}$

Moles of sulfuric acid = 0.002 mol

Moles of $H^+$ = 0.004 mol

Moles of sodium hydroxide in 30 ml of 0.1 M solution.

$0.1 M=\frac{Moles}{0.03 L}$

Moles of sodium hydroxide = 0.003 mol

Moles of $OH^-$ ion = 0.003 mol

Moles of unreacted $H^+$ ions left = 0.004 mol-0.003 mol=0.001 mol

Total volume of solution on mixing = 20 ml = 30 ml = 50 ml = 0.05 L

$[H^+]=\frac{0.001 mol}{0.05 L}=0.02 M$

The molarity of $H^+$ ions in the solution is 0.02 M.