You are diluting a base. You start with 124 mL of 8M and add enough water to make 500mL of solution. What is?

Question

the new Molarity?

Answer 1

Molarity is defined as moles per liter. So what you need to find out is how many moles are in your starting amount, then recalculate the new molarity in the dilution.

124mL = 0.124L
0.124L x 8mol/L = 0.992mol (Liters cancel out)
500mL = 0.5L
0.992mol/0.5L = 1.98mol/L or 1.98M

If you are given that the original solution is 8M and not 8.00M, then the answer rounds to 2M

Answer 2

124 mL of 8M sol contain (124 x 8)/1000 moles of base (because 1000 mL solution 8M have 8 moles of base).
These moles will be contained in 500 mL solution. !000 mL will contain 2x(124x8)/1000 moles. This is the new molarity.

Answer 3

molarity (1) X volume (1) = molarity (2) X volume (2)

(8 M)(124 mL) = (? M)(500 mL)

(8 M)(124 mL) / (500 mL) = ? M

Answer 4

You need to use the formula
(M1)(V1) = (M2)(V2)

M stands for Molarity
V stands for volume which needs to be in mL.

(.124)(8) = (M2)(.500)


((.124M)x(8))/(.500L)

The answer is: 2M

because of one significant digit in 8M.