Question

Concentration Question#1: What is the concentration in g/L if you dissolve 25 grams of sugar in 2 liters of water? (Don't forget units)

Concentration Question#2: What is the concentration in g/L if you dissolve 100 grams of additive in 750 ml of water? (Don't forget units)

Percent by Volume Question #1: What is the percent solution of 50 ml pure rubbing alcohol in 200 ml of water? (Don't forget units)

Percent by Volume Question #2: How much hydrogen peroxide is there in 200 ml of 3% hydrogen peroxide? (Don't forget units)

Answer 1

`\boxed{\text{A1: 12.5 g/L ; A2: 133 g/L; B1: 20 \% by volume; B2: 6 mL}}`

Step-by-step explanation:

A. Concentration

Question 1

`\begin{array}{rcl}\text{Concentration} & = & \frac{\text{Mass of solute}}{\text{Volume of solution}}\\\\& = & \frac{\text{25 g}}{\text{2 L}}\\\\& = &\textbf{12.5 g/L}\\\end{array}\\\text{The concentration of sugar is $\boxed{\textbf{12.5 g/L}}$}`

Question 2

`\begin{array}{rcl}\text{Concentration} & = & \frac{\text{100 g}}{\text{0.750 L}}\\\\& = &\textbf{133 g/L}\\\end{array}\\\text{The concentration of the additive is $\boxed{\textbf{133 g/L}}$}`

B. Percent by volume

Question 1

The formula for percent by volume is

`\text{Percent by volume} = \frac{\text{Volume of solute}}{\text{Volume of solution}}* 100 \, \%`

If your solution contains 50 mL of rubbing alcohol and 200 mL of water, the volume of solution is 250 mL,

`\begin{array}{rcl}\\\text{Percent by volume} & = & \frac{\text{50 mL}}{\text{250 mL}}* 100 \, \%\\\\& = & 20 \, \%\\\end{array}\\\text{The concentration of the solution is $\large \boxed{\textbf{20 \% by volume}}$}`

Question 2

If you have 300 mL of a solution that is 2 % v/v H₂O₂,

`\begin{array}{rcl}2 \, \% & = & \frac{\text{Volume of H$_(2)$O}_(2)}{\text{300 mL}}* 100 \, \%\\\\2 * \text{300 mL} & = & \text{Volume of H$_(2)$O}_(2) * 100\\\\\text{Volume of H$_(2)$O}_(2) & = & \frac{2 * 300\text{ mL}}{100}\\\\ & = & \textbf{6 mL}\\\end{array}\\\text{The volume of H$_(2)$O$_(2)$ in the solution is $\large \boxed{\textbf{6 mL}}$}`