Answer:
493 mL has to evaporate
Explanation:
Step 1: Data given
Initial volume of the sodium chloride (NaCl) solution = 750 mL = 0.750 L
Molarity of the sodium chloride (NaCl) solution = 1.2 M
The concentration needed = 3.5 M
Step 2: Calculate the volume needed
To have a higher concentration we should lower the volume
C1*V1 = C2*V2
⇒C1 = the original concentration = 1.2 M
⇒V1 = the initial volume = 0.750 L
⇒C2 = the new concentration = 3.5 M
⇒V2 = the new volume needed = TO BE DETERMINED
1.2 M * 0.750 L = 3.5 M * V2
V2 = 0.257 L
To have a concentration of 3.5 M we need 0.257 L or 257 mL
Step 3: Calculate the volume of water to evaporate
750 mL - 257 = 493
493 mL has to evaporate
