Question

a chemist adds 0.25 l of a 5.30m sodium nitrate (nano₃) solution to a reaction flask. calculate the moles of sodium nitrate the chemist has added to the flask. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Recall molarity formula

Molarity ($M$) = $\frac{\text{moles of solute}(n)}{\text{volume of solution in liters}(V)}$, so $n = M\times V$.

Step2: Substitute given values

Given $M = 5.30\ M$ and $V=0.25\ L$. Then $n=5.30\ mol/L\times0.25\ L$.

Step3: Calculate moles

$n = 5.30\times0.25=1.325\ mol$.
Rounding to 2 significant digits (since 0.25 has 2 significant digits), $n = 1.3\ mol$.

Answer:

$1.3$