Question

1. An alcohol – water is 65%. How much solution is required to obtain 180.mL of alcohol.

2. Calculate the mass percentage of Na2SO4 in solution containing 11.7 g of Na2SO4 in 443g of Water

3.The word “ proof” in alcoholic drinks refers to the percentage volume of alcohol multiplied by 2. What does 70 proof mean?

4.A 25. 0 grams of an Aqueous NaCl solution is evaporated and found to contain 2.0 grams of NaCl. What is the percent by mass of NaCl in this solution?

5.What is percent composition by volume concentration of a solution on which 75.0ml

6.Find the percent composition by mass in which 41.0g of NaCl is dissolved in 331 grams of water.
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Answer 1

Answer:

5 is the answer because it is

Answer 2

(1)

Given :

An alcohol – water is 65%

To Find :

How much solution is required to obtain 180.mL of alcohol.

Solution :

65% alcohol is present in water

65 ml of alcohol is present in 100 ml of water

1 ml of alcohol is present in $\frac{100}{65}$ ml of water

180 ml of alcohol is present in $\frac{100}{65}$×180 ml of water

                                               = 277 ml of water.

∴ 277 ml of solution is required to obtain 180 ml of alcohol.

(2)

Given :

11.7 g of Na$_{2}$SO$_{4}$ is present in 443g of Water

To Find :

The mass percentage of Na$_{2}$SO$_{4}$ in solution

Solution :

Percent of mass = $\frac{Mass of solute}{Total mass}$×100

                           = $\frac{11.7}{443}$ × 100

                           = 2.64%

∴ The mass percentage of Na$_{2}$SO$_{4}$ in solution containing 11.7 g of Na$_{2}$SO$_{4}$  in 443g of Water is 2.64%.

(3)

Alcohol proof is a measure of the content of ethyl alcohol in an alcoholic beverage. The term was originally used in England where alcohol proof is defined as being double the amount of alcohol by volume (ABV). So if an alcoholic beverage is 35 percent alcohol by volume, it is a 70-proof.

(4)

Given :

mass of Aqueous NaCl = 25 g

Mass of NaCl = 2 g

To Find :

The percent by mass of NaCl in the solution

Solution :

Percent by mass of NaCl = $\frac{Mass of NaCl}{Mass of Solution}$ × 100

                                               = $\frac{2}{25}$×100

                                               = 8%

(5) This question is incomplete. The full question would be

What is percent composition by volume concentration of a solution on which 75.0ml of ethanol is diluted to a volume of 250.0ml?

Given :

volume of ethanol = 75 ml

volume of solvent = 250 ml

To Find :

Percent Composition

Solution :

Percent by volume = $\frac{Volume of Solute}{(Volume of solute) + (Volume of Solvent)}$× 100

                                = $\frac{75}{75 + 250}$ × 100

                                = 23.1%

(6)

Given :

mass of NaCl = 41 g

Mass of water = 331 g

To Find : Percent composition

Solution :

Percentage by mass of NaCl = $\frac{Mass Of NaCl}{(Mass of NaCl) + (Mass of Water)}$ ×100

                                                = $\frac{41}{41 + 331}$ × 100

                                                = $\frac{41}{372}$ × 100

                                                = 11.02%

∴ The percent composition by mass in which 41.0g of NaCl is dissolved in 331 grams of water is 11.02%.