molarity of?

Question

What will be the molarity of the resulting solution made by mixing 100. mL of 12 M HCl + 200. mL H2O?

Answer 1

The final volume is 200+100 =300ml so the dilution is 100/300 =1/3

and 12M/3 = 4M

molarity 4M

Answer 2

Hello Kady,
adding on to Maussy's answer. He/She knows how to work to get to the answer but he/she does not explain how it is worked.

Solution Dilution- deals with stock solutions.
Msub1Vsub1=Msub2Vsub2
(A). Msub1=12M The starting Molarity of HCL
(B). Vsub1=.1L The starting volume is 100mL or .1L
(C). Vsub2= .3L The ending of the Solution (the solvent plus the Solute) what is getting dissolved in what.

so you have to solve the problem
Msub2=(((Msub1)(Vsub1))/Vsub2)
Msub2=(((12M)(.1L))/.3L)
Msub2=4.