Question

The molarity of a solution obtained by mixing 750 mL of 0.5 (M) HCl with 250 mL of 2(M) HCl will be.............?

Answer 1

tha resultant molar it when two acids or two bases are mixed is given by
M = M1V1+M2V2 / V1+V2
SO ,
M = 750*0.5 + 250*2 / 750+250
M = 375 + 500 / 1000
M = 875 /1000 = 0.875 M

Answer 2

Answer: 0.875

Explanation:

$M_1V_1+M_2V_2=M_3(V_1+V_2)$

where $M_1$= molarity of ist solution of $HCl$ = 0.5M

$V_1$ = volume in Liters of ist solution of $HCl$ = 750 ml = 0.75 L

$M_2$ = molarity of 2nd solution of $HCl$ = 2M

$V_2$ = volume in Liters of 2nd solution of $HCl$ = 250 ml = 0.25 L

$M_3$ = molarity of resulting solution of $HCl$ = ?

Putting in the values:

$0.5M\times 0.75L+2M\times 0.25L=M_3(1.0L)$

$M_3=0.875M$