Question

The molar concentration of H+ ions when 300 ml of water is added in 0.1 M 200 ml of H2SO4 solution is

Answer 1

initial molar concentration of H2SO4 , $M_1$ = 0.1M

volume of solution , $V_1$ = 200mL

after adding 300mL of water ,

new volume of solution, $V_2$ = (300 + 200)mL = 500mL

we know, $M_1V_1=M_2V_2$

so, 0.1 × 200 = $M_2$ × 500

or, $M_2$ = 0.1 × 0.4 = 0.08M

hence, molar concentration of H2SO4 = 0.08M

we know, 1 mole of H2SO4 contains 2 mole of H+ ions

so, molar concentration of H+ ions = 2 × 0.08M = 0.16M

Answer 2

its 0.08 M.... you just ahve to add the volumes and then apply the formula

M1V1=M2V2