1. What is the percent by mass of a solution that contains 50 grams of solute dissolved in 200 grams of solution? What is the concentration of the same solution in parts per million?

2. What is the percent mass of a solution that contains 75 grams of salt dissolved in 150 grams of water? What is the concentration of the same solutionin parts per million?

3. If a solution is 25% NaCl by mass, what is the mass of salt contained in 150 grams of the solution?

4. What mass of solute is needed to prepare 500 grams of a 15% by mass solution?

5. What mass of sugar is present in 2.50 kilograms of solution that is 30% by mass?

6. What is the mass of solute present in 250 grams of a solution that is 12% by mass?

7. The average salinity off sea water is 34.7%. What is this quantity expressed in parts per million?

1. What is the percent by mass of a solution that contains 50 grams of solute dissolved in 200 grams of solution? What is the concentration of the same solution in parts per million?

% w/w = (g solute/g soln)*100 = 25% w/w\.

25g/100 = ??ppm.
What must you multiply 100 by to get 1,000,000? That would be 10^4. So multiply 25 by 10^4 and you will have 2.5^10^4/10^6 = 250,000 ppm

1. To find the percent by mass of a solution, we need to divide the mass of the solute by the mass of the solution and multiply by 100.

Mass of solute = 50 grams
Mass of solution = 200 grams

Percent by mass = (mass of solute / mass of solution) x 100
Percent by mass = (50 grams / 200 grams) x 100
Percent by mass = 25%

To find the concentration in parts per million (ppm), we multiply the percent by mass by 10,000.

Concentration in ppm = Percent by mass x 10,000
Concentration in ppm = 25% x 10,000
Concentration in ppm = 250,000 ppm

2. Similar to problem 1:

Mass of solute = 75 grams
Mass of solution = 150 grams

Percent by mass = (mass of solute / mass of solution) x 100
Percent by mass = (75 grams / 150 grams) x 100
Percent by mass = 50%

Concentration in ppm = Percent by mass x 10,000
Concentration in ppm = 50% x 10,000
Concentration in ppm = 500,000 ppm

3. To find the mass of salt in a solution, we multiply the percent by mass by the mass of the solution.

Percent by mass = 25%
Mass of solution = 150 grams

Mass of salt = Percent by mass x Mass of solution
Mass of salt = 25% x 150 grams
Mass of salt = 0.25 x 150 grams
Mass of salt = 37.5 grams

4. To find the mass of solute needed to prepare a solution, we multiply the desired percent by mass by the total mass of the solution.

Desired percent by mass = 15%
Total mass of solution = 500 grams

Mass of solute = Desired percent by mass x Total mass of solution
Mass of solute = 15% x 500 grams
Mass of solute = 0.15 x 500 grams
Mass of solute = 75 grams

5. To find the mass of sugar in a solution, we multiply the percent by mass by the total mass of the solution.

Percent by mass = 30%
Total mass of solution = 2.50 kilograms = 2500 grams

Mass of sugar = Percent by mass x Total mass of solution
Mass of sugar = 30% x 2500 grams
Mass of sugar = 0.30 x 2500 grams
Mass of sugar = 750 grams

6. Similar to problems 1 and 2:

Percent by mass = 12%
Mass of solution = 250 grams

Mass of solute = Percent by mass x Mass of solution
Mass of solute = 12% x 250 grams
Mass of solute = 0.12 x 250 grams
Mass of solute = 30 grams

7. To convert percent to parts per million, we multiply by 10,000.

Percent = 34.7%

Salinity in ppm = Percent x 10,000
Salinity in ppm = 34.7% x 10,000
Salinity in ppm = 347,000 ppm

1. To find the percent by mass of a solution, you need to divide the mass of the solute by the mass of the solution and then multiply by 100. In this case, the mass of the solute is 50 grams and the mass of the solution is 200 grams. So, the percent by mass can be calculated as (50 g / 200 g) * 100 = 25%.

To convert the concentration to parts per million (ppm), you can multiply the percent by mass by 10,000. So, in this case, the concentration in parts per million would be 25% * 10,000 = 250,000 ppm.

2. Similar to the previous question, to find the percent by mass of the solution, you need to divide the mass of the solute by the mass of the solution and then multiply by 100. In this case, the mass of the solute is 75 grams and the mass of the solution is 150 grams. So, the percent by mass can be calculated as (75 g / 150 g) * 100 = 50%.

To convert the concentration to parts per million (ppm), you can multiply the percent by mass by 10,000. So, in this case, the concentration in parts per million would be 50% * 10,000 = 500,000 ppm.

3. To find the mass of salt contained in 150 grams of a 25% NaCl solution, you need to multiply the mass of the solution by the percent by mass of the solute. In this case, the mass of the solution is 150 grams and the percent by mass of NaCl is 25%. So, the mass of salt can be calculated as 150 g * 0.25 = 37.5 grams.

4. To determine the mass of solute needed to prepare a 15% solution, you need to multiply the desired mass of the solution by the percent by mass of the solute. In this case, the desired mass of the solution is 500 grams and the percent by mass is 15%. So, the mass of the solute can be calculated as 500 g * 0.15 = 75 grams.

5. To find the mass of sugar present in a 2.50 kilogram solution that is 30% by mass, you can multiply the mass of the solution by the percent by mass of the solute. In this case, the mass of the solution is 2.50 kilograms (which is 2500 grams) and the percent by mass of sugar is 30%. So, the mass of sugar can be calculated as 2500 g * 0.30 = 750 grams.

6. Similar to previous questions, to find the mass of solute present in a 250 gram solution that is 12% by mass, you need to multiply the mass of the solution by the percent by mass of the solute. In this case, the mass of the solution is 250 grams and the percent by mass is 12%. So, the mass of the solute can be calculated as 250 g * 0.12 = 30 grams.

7. To express the average salinity of sea water (34.7%) in parts per million, you can multiply the percent by mass by 10,000. In this case, the salinity is 34.7%. So, the concentration in parts per million would be 34.7% * 10,000 = 347,000 ppm.

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