Answer : The volume of water added are, 15 mL
Explanation :
Formula used :
[tex]M_1V_1=M_2V_2[/tex]
where,
[tex]M_1\text{ and }V_1[/tex] are the initial molarity and volume of HCl.
[tex]M_2\text{ and }V_2[/tex] are the final molarity and volume of water.
We are given:
[tex]M_1=12M\\V_1=50mL\\M_2=40M\\V_2=?[/tex]
Putting values in above equation, we get:
[tex]12M\times 50mL=40M\times V_2\\\\V_2=15mL[/tex]
Hence, the volume of water added are, 15 mL
