Question

Please check these for me?

1. Given that magnesium has a MW of 24 and chlorine a MW of 35.5, calculate the number of moles in a 325 dg sample of MgCl2?

My answer: 95 g.

2. What would the molarity of your solution if you dissolved the 325 mg sample of MgCl2 in 5.75 dl

My answer: 0.006 M

Answer 1

Mg = 24.3g/mol + (2*35.4 g/mol) because Cl molar mass 35.4 and there is two in this sample. Equals 95.1 g/mol MgCl2.
But this acts for how many moles. So 325 g/95.1 g/ mol mgcl2
EQUALS 3.42 moles of MgCl2
Now if the question is tricky and you meant to say dg then you will have to change this a bit. I can answer the next question, but is it dg and dL? As in decigram and deciliter?

Answer 2

If it's decigram dg then we need to change that 325 to 32.5. If it's decagram (dag etc) then we need to change the 325 to 3250.

Since it is easier and more normal I am going to assume the dl is just L.
Molarity is just moles per liter. This is based on the first question. So assuming it is grams and liters, we just put moles 3.25/5.75
EQUALS .565 M soln of MgCl2.

If those are both deci then we would have .342 moles of MgCl2.
Then .342/.575 =.595 M soln if those are both deci.