Question

If 272 mL of 0.24MNaCl solution is diluted with water to a volume of 450 mL, the new concentration of solution in correct significant figures is;

a. 0.14
b. 0.145
c. 0.144
d. 0.140

Answer 1

The new concentration of the NaCl solution after dilution is 0.145 M. This is calculated using the dilution equation M1V1 = M2V2 and rounding to two significant figures. Option number b is correct.

Step-by-step explanation:

To calculate the new concentration of a diluted solution, we can use the dilution equation M1V1 = M2V2, where M1 is the initial molarity, V1 is the initial volume, M2 is the final molarity, and V2 is the final volume.

In the given problem, we have M1 as 0.24 M for the NaCl solution, V1 as 272 mL, and V2 as 450 mL. The final concentration (M2) is what we're trying to find.

Plugging the values into the equation, we have:

0.24 M * 272 mL = M2 * 450 mL

Multiple both sides of the equation by 1/450 to isolate M2:

M2 = (0.24 M * 272 mL) / 450 mL

M2 = 0.1448 M

Since we should report our answer with the same number of significant figures as the least precise measurement, and the initial molarity (0.24) has two significant figures, our answer should be rounded to two significant figures as well.

Therefore, the correct answer is b. 0.145 as it is closest to the calculated value and has the correct number of significant figures.