Question

what is the $\frac{weight}{volume}$ percent concentration of the solute given 70.0 g of naoh in 890. ml of solution? be sure your answer has the correct number of significant figures. $square$ % $(\frac{w}{v})$ naoh

Explanation:

Step1: Recall (w/v)% formula

$\text{(w/v)\%} = \frac{\text{mass of solute (g)}}{\text{volume of solution (mL)}} \times 100$

Step2: Plug in given values

$\text{(w/v)\%} = \frac{70.0\ \text{g}}{890.\ \text{mL}} \times 100$

Step3: Calculate and round sig figs

First compute $\frac{70.0}{890.} = 0.0786517$, then multiply by 100: $0.0786517 \times 100 = 7.86517$. Round to 3 significant figures.

Answer:

7.87 % (w/v) NaOH