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Listerine mouthwash has 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.)
how would yu do this problem ?!?!
DrBob222
answered
If that is 21.6%(v/v), it means 21.6 mL EtOH/100 mL soln; therefore, 20 mL will contain
21.6 mL EtOH x (20 mL/100 mL) = ?? mL EtOH.
Then mass = volume x density.
matt
answered
3.40848g.
I put this in and it was right.
Step-by-Step Bot
answered
To solve this problem, you can use the information provided about the percentage of ethyl alcohol by volume and the density of ethanol. Here's the step-by-step process:
Step 1: Convert the volume of mouthwash from milliliters (mL) to liters (L):
20.0 mL = 20.0 ÷ 1000 = 0.020 L
Step 2: Calculate the mass of the mouthwash using the density of ethanol:
Mass = Volume × Density = 0.020 L × 0.789 g/mL = 0.01578 g
Step 3: Determine the mass of ethyl alcohol in the mouthwash using the percentage of ethyl alcohol by volume:
Mass of ethyl alcohol = Mass of mouthwash × Percentage of ethyl alcohol = 0.01578 g × 21.6% = 0.00340608 g
Therefore, there is approximately 0.00340608 g of ethanol contained in 20.0 mL of Listerine mouthwash.
Explain Bot
answered
To find the mass of ethanol contained in 20.0 mL of Listerine mouthwash, we can follow these steps:
Step 1: Calculate the volume of ethanol in 20.0 mL of mouthwash.
Given that Listerine mouthwash contains 21.6% ethyl alcohol by volume, we can calculate the volume of ethanol in 20.0 mL of mouthwash using the formula:
Volume of ethanol = 21.6% x 20.0 mL = 0.216 x 20.0 mL = 4.32 mL
Step 2: Convert the volume of ethanol to mass using the density of ethanol.
The density of ethanol is given as 0.789 g/mL. Since we have the volume of ethanol in mL, we can convert it to grams using the density:
Mass of ethanol = Volume of ethanol x Density of ethanol
Mass of ethanol = 4.32 mL x 0.789 g/mL = 3.407 g
Therefore, the mass of ethanol contained in 20.0 mL of Listerine mouthwash is approximately 3.407 grams.