[andyman20]

Hi
I was stuck in the questions where you have to find the concentration of ions.

The question is:

Calculate the concentration of chloride ions in 10mL of 0.5M MgCl2

a)0.5M
b)1.0M
c)0.5x0.01M
d)0.5/0.01 M

I have done this much...

M=number of moles/volume in metres

0.5=x/0.01

therefore no. of moles = 0.005

I am stuck from here...
please help me.
Thank you

[arnyk]

So you know that there is 0.005 mol of MgCl2 in solution.

For every 1mol of MgCl2, there is 1mol of Mg and 2mol of Cl (as seen in the chemical formula).

Knowing this, if there are 0.005 mol of MgCl2, how many moles of Cl are there?

[xiankai]

M refers to molarity(also known as concentration), and is measured in moles per dm³(1 litre or 1000 cm³ too)