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| 1 | |
Which of the following is not an acceptable way to express concentration? |
| | A) | Mass of solute/volume of solution |
| | B) | Mass of solute/mass of solution |
| | C) | Mass of solute/100 g of water |
| | D) | Volume of solute/volume of solution |
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| 2 | |
A student adds 6.00 g of a solid to 30.0 mL of water. What is the concentration of this solution expressed as mass/volume percent? (If necessary to the calculation, assume that 1.00 mL of water has a mass of 1.00 g and that the total volume remains 30.0 ml.) |
| | A) | 0.200% (m/v) |
| | B) | 16.7% (m/v) |
| | C) | 20.0% (m/v) |
| | D) | 500% (m/v) |
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| 3 | |
A student adds 6.00 g of a solid to 30.0 mL of water. What is the concentration of this solution expressed as mass/mass percent? (Assume the volume of the solution remains 30.0 mL and, if necessary to the calculation, assume that 1.00 mL of water has a mass of 1.00 g.) |
| | A) | 0.167% (m/m) |
| | B) | 0.200% (m/m) |
| | C) | 16.7% (m/m) |
| | D) | 20.0% (m/m) |
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| 4 | |
A student adds 6.00 g of a solid to 30.0 mL of water. The solid has a molar mass of 72.0 g/mol. What is the molar concentration of the solution? (If necessary to the calculation, assume that 1.00 mL of water has a mass of 1.00g and that the solution volume is 30.0 mL.) |
| | A) | 2.78 mol/L |
| | B) | 0.00278 mol/L |
| | C) | 0.00250 mol/L |
| | D) | 0.360 mol/L |
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| 5 | |
An environmental toxin is present in an extremely small amount in a sample of river water. What is the best way to report its concentration? |
| | A) | mol/L |
| | B) | %(v/v) |
| | C) | %(m/m) |
| | D) | ppm |
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| 6 | |
What mass of solute is present in 250. mL of a 0.100 mol/L solution of NaOH (molar mass of NaOH = 40.00 g/mol)? |
| | A) | 0.625 g |
| | B) | 1.00 g |
| | C) | 6.25 g |
| | D) | 1000 g |
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| 7 | |
A student dilutes 50.0 mL of a 0.10 mol/L solution of HCl to 0.010 mol/L by adding water. Which statement is true? |
| | A) | The volume of the solution remains the same. |
| | B) | The volume of the solvent remains the same. |
| | C) | The total amount of solute remains the same. |
| | D) | The total amount of solute decreases. |
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| 8 | |
When preparing a dilute acid solution from a concentrated acid solution, |
| | A) | adding the acid to the water aids the mixing process |
| | B) | adding the acid to the water prevents the splattering of hot acid |
| | C) | wear appropriate protective clothing and goggles and work in a fume hood |
| | D) | all of the above are true |
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| 9 | |
How would you prepare 500.0 mL of a 2.00 mol/L solution of HCl from a concentrated solution of 12.0 mol/L? |
| | A) | To some water in a 500.0 mL volumetric flask, add 83.3 mL of concentrated acid, then dilute to the mark. |
| | B) | To some water in a 500.0 mL volumetric flask, add 8.33 mL of concentrated acid, then dilute to the mark. |
| | C) | To some water in a 500.0 mL volumetric flask, add 3.00 mL of concentrated acid, then dilute to the mark. |
| | D) | Pour 83.3 mL of concentrated acid into a 500.0 mL volumetric flask. Dilute with water to the mark. |
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