Question

What volume (in mL) of concentrated HCl (12 M) is needed to make 1500 mL of a 3.5 M solution?

Answer 1

437.5 mL

Step-by-step explanation:

Concentration (c) = Moles (n) / Volume of solution (liters)

C = n / V

rearrange the formula to find out how many moles you need in the final solution.

n (moles) = concentration (c) x Volume (V) ( in liters)

Convert your mL into L. 1500mL is 1.5L

n = 3.5 moles/liter x 1.5 liters (the liters cancel each other out)

n = 5.25 moles

Now use the same formula to calculate the volume you need to make the final solution based on the concentration of the original.

c = n/V or V = n / c

V = 5.25 moles / 12 moles/liter here the moles cancel out

V = 0.4375 L

convert back to mL

V = 437.5 mL