Question

calculate the concentration of sodium chloride present in mass % for a solution of 45 g of salt in 1200 ml of water. the density of water is 1.00 g/ml. be sure to take the solute into account for the total solution mass. 27% 3.8 % 3.6% 4.1 % question 24 1 pts calculate the mass of sodium chloride in a 10% aqueous solution if the total mass of the solution is 350 grams. 0.035 g 0.35 g 3.5 g 35 g

Explanation:

Step1: Calculate mass of water

Use density formula $m =
ho V$. Given $
ho = 1.00\ g/mL$ and $V = 1200\ mL$, so $m_{water}=
ho V=1.00\ g/mL\times1200\ mL = 1200\ g$.

Step2: Calculate total mass of solution

Total mass of solution $m_{solution}=m_{solute}+m_{water}$. Here $m_{solute} = 45\ g$ and $m_{water}=1200\ g$, so $m_{solution}=45\ g + 1200\ g=1245\ g$.

Step3: Calculate mass - percentage of solute

Mass - percentage formula is $\text{Mass}\%=\frac{m_{solute}}{m_{solution}}\times100\%$. Substitute $m_{solute} = 45\ g$ and $m_{solution}=1245\ g$ into the formula: $\text{Mass}\%=\frac{45\ g}{1245\ g}\times100\%\approx3.6\%$.

Step4: Solve for second - question

Use the formula $\text{Mass}\%=\frac{m_{solute}}{m_{solution}}\times100\%$. Rearrange it to find $m_{solute}=\text{Mass}\%\times m_{solution}\div100\%$. Given $\text{Mass}\% = 10\%$ and $m_{solution}=350\ g$, so $m_{solute}=10\%\times350\ g\div100\% = 35\ g$.

Answer:

Question 23: C. 3.6%
Question 24: D. 35 g