Question

A 45% sucrose solution lost 260 mL by evaporation. After evaporation what is the sucrose concentration in the remaining 300 mL? Round your final answer to 2 decimal places if necessary.

Answer 1

84%

Step-by-step explanation

the concentration is given by

`\text{concentration = }\frac{volume\text{ of sucrose}}{\text{total volume}}\cdot100\text{ \%}`

hence

Step 1

for the initial solution

`45\text{ \%=}\frac{volumesucre}{\text{total volume}}\cdot100\rightarrow equation(1)`

Step 2

after the evaporation

`\begin{gathered} x\text{ \%=}\frac{volumesucrose}{(initial\text{ volume-evaporatio)}} \\ x\text{ \%=}\frac{volumesucrose}{(initial\text{ volume-260)}=300} \\ x\text{ \%=}(volumesucrose)/(300)\rightarrow equation(2) \end{gathered}`

`\begin{gathered} (initial\text{ volume-260)}=300 \\ add\text{ 260 in both sides} \\ (initial\text{ volume-260)+260}=300+260 \\ initial\text{ volume=560} \end{gathered}`

now, replace this value in step 1 to find the initial volume of sucrose

`\begin{gathered} 45\text{ \%=}\frac{volumesucre}{\text{5}60} \\ 0.45\cdot560mL=\text{volume sucrose} \\ 252\text{ mL = Volume of sucrose} \end{gathered}`

now, replace this value in eq(2)

`\begin{gathered} x\text{ \%=}(volumesucrose)/(300)\rightarrow equation(2) \\ x\text{ \%=}(252)/(300)\cdot100 \\ x\text{ \%=84 \%} \end{gathered}`

therefore, the answer is

84%

I hope this helps you