Question

35 grams of ethanol is dissolved in 115 grams of water. What is the concentration of ethanol in parts per million

Answer 1

The concentration of ethanol in ppm is 23,3333.33ppm

Step-by-step explanation

Given that

The mass of ethanol dissolved in water is 35 grams

The mass of the water is 115 grams

Follow the steps below to find the concentration of ethanol

Recall, that the ethanol is the solute and the water is the solvent

Solution = solute + solvent

Hence, the mass of the solution is calculated below as

Mass of the solution = 35 + 115

Mass of the solution = 150 grams

The next step is to calculate the concentration of ethanol

`\begin{gathered} \text{ \% concentration = }\frac{\text{ Mass of the solute}}{\text{ mass of the solution}}\text{ }*\text{ 100\%} \\ \\ \text{ \% concentration = }(35)/(150)*\text{ 100\%} \\ \text{ \% concentration of ethanol = 0.2333}*\text{ 100\%} \\ \text{ \% concentration of ethanol = 23.33\%} \end{gathered}`

Convert the percentage to part per million

`\begin{gathered} \text{ 1\% }\rightarrow\text{ 10000ppm} \\ \text{ 23.3\% }\rightarrow\text{ xppm} \\ \text{ cross multiply } \\ \text{ x = 23.3 }*\text{ 10000} \\ \text{ x = 23,3333.33ppm} \end{gathered}`

Therefore, the concentration of ethanol in ppm is 23,3333.33ppm