Measuring weight to give me mg/L

Its been a while since i've done this calculation so could someone tell me where i go from here please:

I need 1L of 10,000 mg/L of Cl. I have CaCl2

MW of CaCl2 = 110.98
MW of Cl=35.44

110.98/35.44 = 3.131

10000 * 3.121= 31314g if i wanted 1kg per L

This is the part i get stuck at, instinctively i know i need a lot less but where do i go. Thank you for any help

[JohnS]

Originally Posted by Charleydaves

Its been a while since i've done this calculation so could someone tell me where i go from here please:

I need 1L of 10,000 mg/L of Cl. I have CaCl2

MW of CaCl2 = 110.98
MW of Cl=35.44

110.98/35.44 = 3.131

10000 * 3.121= 31314g if i wanted 1kg per L

This is the part i get stuck at, instinctively i know i need a lot less but where do i go. Thank you for any help

1) Note that 10000 mg = 10 g
2) You want 10 g x 1 mol/35.44 g = 0.28217 mol of CL
3) Because there are two Cl atoms, you only want 0.14108 mol of CaCl2.
4) 0.14108 mol x 110.98 g/mol = 15.66 g CaCl2.

Thank you for the great reply, i see where my logic should have taken me.