Which of the following is least concentrated?JUSTIFY your answer?

Question

a.0.003 mol/100mL solution
b.0.003 mol/100mL solvent
c.0.05 mol/10L solution
d.0.20mol/1L solution

Answer 1

first of convert all into mol/L-
a)-0.003 mol/100mL=0.03 mol/1000mL
=0.03 mol/L solution
b)-0.003 mol/100mL= 0.03 mol/L solvent
c)-0.05 mol/10L=0.005 mol/L solution
d)-0.20mol/1L solution

so the correct answer is (c)

Answer 2

Well what they want you to do is work out the concentration in mol dm^ -3

convert each of the volumes in to dm ^ 3

100 ml = 0.1 dm ^ 3
10 L = 10 dm ^ 3
1 L = 1 dm ^ 3

so use concentration = moles/volume

a = 0.003/0.1 = 0.03 mols dm ^ -3
b = the same as a (solvent is just another word for anything you would dissolve it in: eg water)
c = 0.05/10 = 0.005 mol dm ^ -3
d = 0.2/ 1 = 0.2 mol dm ^ -3

btw dm ^ 3 means decimetres cubed and ^ - 3 means per decimetre cubed

Answer 3

Solve this by changing mL to L and then do the division. The lowest value is the least concentrated!