Question

A chemist dilutes a 1.0 mL sample of 2.0 M KNO3 by adding water to it. If the concentration of the solution that is obtained is 0.0080 M, what is its volume?
Use M subscript i V subscript i equals M subscript f V subscript f..
125 mL
250 mL

Answer 1

To find the final volume of the solution after dilution, we can use the dilution equation:

\[
M_i V_i = M_f V_f
\]

Where:
- \(M_i\) is the initial concentration (2.0 M)
- \(V_i\) is the initial volume (1.0 mL)
- \(M_f\) is the final concentration (0.0080 M)
- \(V_f\) is the final volume, which we want to find.

Plugging in the values we have:

\[
(2.0 \, \text{M})(1.0 \, \text{mL}) = (0.0080 \, \text{M})(V_f)
\]

Calculating the left side:

\[
2.0 \, \text{M} \times 1.0 \, \text{mL} = 2.0 \, \text{M mL}
\]

Setting the two sides equal:

\[
2.0 \, \text{M mL} = (0.0080 \, \text{M})(V_f)
\]

To solve for \(V_f\):

\[
V_f = \frac{2.0 \, \text{M mL}}{0.0080 \, \text{M}}
\]

Calculating \(V_f\):

\[
V_f = \frac{2.0}{0.0080} = 250 \, \text{mL}
\]

Therefore, the final volume of the solution is **250 mL**.