Question

what is the molarity of a HCl solution that contains 13.0 g of HCl in 125 mL of solution?
Answer in units of M

is it 3791.944 ?

Answer 1

No, not close.
Show your work and I'll find the error.

Answer 2

13(36.461)=473.993

473.993/.125=3791.944

Answer 3

mol = g/molar mass
You multiplied. You should divide.
13.0/36.461 = ?
Then ?/0.125 = x

Answer 4

2.852

Answer 5

Some profs would not give you credit for that answer even though it is close. The correct answer is 2.85M. Why is 2.852 wrong? Because you are allowed only three significant figures (dictated by 3 in 13.0 and 3 in 125); therefore, you may have only 3 in the answer. 2.85 satisfies that and 2.852 does not for it has 4 s.f.