Listerine mouthwash is 21.6% ethyl alcohol by volume. What mass of ethanol is contained in 20.0 mL of mouthwash? (The density of ethanol is 0.789 g/mL.)
Answer in units of grams
21.6% EtOH means 21.6 g EtOH/100 mL solution; therefore, 20 mL will contain
21.6g x (20 mL/100 mL) = about 4 mL EtOH but you should be more accurate than that.
Then mass = volume x density.
You have volume and density, solve for mass.
To find the mass of ethanol contained in 20.0 mL of Listerine mouthwash, we need to first calculate the volume of ethanol present in 20.0 mL of mouthwash.
Given:
Volume of mouthwash = 20.0 mL
Ethanol concentration = 21.6% by volume
Step 1: Calculate the volume of ethanol in 20.0 mL of mouthwash.
Volume of ethanol = Ethanol concentration * Volume of mouthwash
Volume of ethanol = 21.6% * 20.0 mL
Volume of ethanol = 0.216 * 20.0 mL
Volume of ethanol = 4.32 mL
Step 2: Convert the volume of ethanol to mass using the density of ethanol.
Mass of ethanol = Volume of ethanol * Density of ethanol
Mass of ethanol = 4.32 mL * 0.789 g/mL
Mass of ethanol = 3.40608 g
Therefore, the mass of ethanol contained in 20.0 mL of Listerine mouthwash is approximately 3.40608 grams.
To find the mass of ethanol in 20.0 mL of Listerine mouthwash, we need to calculate the amount of ethanol in the given volume.
First, we need to determine the volume of ethanol in 20.0 mL of mouthwash. Since Listerine mouthwash is 21.6% ethyl alcohol by volume, we can find this using the equation:
Volume of ethanol = 21.6% × 20.0 mL
Next, we need to convert the volume of ethanol to mass. To do this, we'll use the density of ethanol, which is given as 0.789 g/mL.
Mass of ethanol = Volume of ethanol × density of ethanol
Now, let's substitute the values into the equation:
Mass of ethanol = (21.6% × 20.0 mL) × 0.789 g/mL
Simplifying the calculation:
Mass of ethanol = (0.216 × 20.0) × 0.789 g
Mass of ethanol = 4.32 × 0.789 g
Mass of ethanol = 3.408 g
Therefore, the mass of ethanol contained in 20.0 mL of Listerine mouthwash is 3.408 grams.