When 50. milliliters of an HNO3 solution is
exactly neutralized by 150 milliliters of a 0.50 M
solution of KOH, what is the concentration of
HNO3?
(1) 1.0 M (3) 3.0 M
(2) 1.5 M (4) 0.5 M



Answer :

The reaction formula is HNO3 + KOH = KNO3 + H2O. The mole number of HNO3 and KOH is the same. So the concentration of HNO3 is 150*0.5/50=1.5 M. So the answer is (2).

Answer : The correct option is, (2) 1.5 M

solution :

According to the neutralization law,

[tex]M_1V_1=M_2V_2[/tex]

where,

[tex]M_1[/tex] = molarity of [tex]HNO_3[/tex] solution = ?

[tex]V_1[/tex] = volume of [tex]HNO_3[/tex] solution =  50 ml

[tex]M_2[/tex] = molarity of KOH solution = 0.50 M

[tex]V_2[/tex] = volume of KOH solution = 150 ml

Now put all the given values in the above law, we get the volume of [tex]HNO_3[/tex] solution.

[tex]M_1\times (50ml)=(0.50M)\times (150ml)[/tex]

[tex]M_1=1.5M[/tex]

Therefore, the concentration of [tex]HNO_3[/tex] is, 1.5 M