Question

what is the molarity of a solution prepared using the given amount of solute and total volume of solution? part 1 of 2 7.9 mol of naoh in 6.10 l of solution. be sure your answer has the correct number of significant figures. m naoh part 2 of 2 43.7 g of nano₃ in 480. ml of solution. be sure your answer has the correct number of significant figures. m nano₃

Explanation:

Part 1 of 2

Step1: Recall the formula for molarity

Molarity ($M$) is defined as the number of moles of solute ($n$) divided by the volume of the solution in liters ($V$). The formula is $M=\frac{n}{V}$.

Step2: Substitute the given values into the formula

We are given $n = 7.9\space mol$ of $NaOH$ and $V=6.10\space L$.

$$M=\frac{7.9\space mol}{6.10\space L}$$

Step3: Calculate the molarity

$$M=\frac{7.9}{6.10}\space M\approx1.3\space M$$

(rounded to two significant figures, since 7.9 has two significant figures and 6.10 has three, and the rule for division is to go by the least number of significant figures in the values used in the calculation)

Part 2 of 2

Step1: Calculate the molar mass of $NaNO_3$

The molar mass of $Na$ is $22.99\space g/mol$, $N$ is $14.01\space g/mol$, and $O$ is $16.00\space g/mol$.

$$M_{NaNO_3}=22.99 + 14.01+3\times16.00=85.00\space g/mol$$

Step2: Calculate the number of moles of $NaNO_3$

Using the formula $n=\frac{m}{M}$, where $m = 43.7\space g$ and $M = 85.00\space g/mol$

$$n=\frac{43.7\space g}{85.00\space g/mol}\approx0.514\space mol$$

Step3: Convert the volume of the solution to liters

Given $V = 480\space mL$, since $1\space L=1000\space mL$, then $V=\frac{480}{1000}\space L = 0.480\space L$

Step4: Calculate the molarity

Using the formula $M=\frac{n}{V}$, substitute $n = 0.514\space mol$ and $V = 0.480\space L$

$$M=\frac{0.514\space mol}{0.480\space L}\approx1.07\space M$$

(rounded to three significant figures, 43.7 has three, 480 (as 0.480) has three)

Answer:

• Part 1 of 2: $1.3\space M\space NaOH$
• Part 2 of 2: $1.07\space M\space NaNO_3$