quiz

A chef wants to boil water for soup as quickly as possible. She uses filtered water instead of salty or mineral-rich water. Explain scientifically why this is a good choice and how impurities affect boiling point. (2 marks)

A chef wants to boil water for soup as quickly as possible. She uses filtered water instead of salty or mineral-rich water. Explain scientifically why this is a good choice and how impurities affect boiling point. (2 marks)

The diagram below shows two ice cubes. Cube A is pure ice. Cube B has salt sprinkled on it. Both are left in the same room temperature conditions.After 5 minutes, Cube B has melted more than Cube A. Explain scientifically why this happened. (2 marks)

The diagram below shows two ice cubes. Cube A is pure ice. Cube B has salt sprinkled on it. Both are left in the same room temperature conditions.After 5 minutes, Cube B has melted more than Cube A. Explain scientifically why this happened. (2 marks)

The diagram below shows two ice cubes. Cube A is pure ice. Cube B has salt sprinkled on it. Both are left in the same room temperature conditions.After 5 minutes, Cube B has melted more than Cube A. Explain scientifically why this happened. (2 marks)

The diagram below shows a heating curve for two liquids. Curve A is for pure water, and Curve B is for salty water.Use the diagram to explain the effect of impurities on the boiling point. (2 marks)

The diagram below shows a heating curve for two liquids. Curve A is for pure water, and Curve B is for salty water.Use the diagram to explain the effect of impurities on the boiling point. (2 marks)

The diagram below shows a heating curve for two liquids. Curve A is for pure water, and Curve B is for salty water.Use the diagram to explain the effect of impurities on the boiling point. (2 marks)

The diagram below shows a heating curve for two liquids. Curve A is for pure water, and Curve B is for salty water.Use the diagram to explain the effect of impurities on the boiling point. (2 marks)

Linnet is melting stearic acid. Her impure sample melts from 52°C to 57°C, while her teacher’s pure sample melts sharply at 55°C. What can she conclude? (1 mark)

Linnet is melting stearic acid. Her impure sample melts from 52°C to 57°C, while her teacher’s pure sample melts sharply at 55°C. What can she conclude? (1 mark)

Linnet is melting stearic acid. Her impure sample melts from 52°C to 57°C, while her teacher’s pure sample melts sharply at 55°C. What can she conclude? (1 mark)

Mary heats two samples of wax. The pure wax melts sharply at 65°C, while the impure wax melts gradually starting at 58°C. What can she conclude? (1 mark)

Mary heats two samples of wax. The pure wax melts sharply at 65°C, while the impure wax melts gradually starting at 58°C. What can she conclude? (1 mark)

Mary heats two samples of wax. The pure wax melts sharply at 65°C, while the impure wax melts gradually starting at 58°C. What can she conclude? (1 mark)

Mary heats two samples of wax. The pure wax melts sharply at 65°C, while the impure wax melts gradually starting at 58°C. What can she conclude? (1 mark)

A chemistry student compares pure wax and wax mixed with sand. The impure wax melts at a lower temperature and more slowly. What causes this change?  (1 mark)

A chemistry student compares pure wax and wax mixed with sand. The impure wax melts at a lower temperature and more slowly. What causes this change?  (1 mark)

A chemistry student compares pure wax and wax mixed with sand. The impure wax melts at a lower temperature and more slowly. What causes this change?  (1 mark)

A chemistry student compares pure wax and wax mixed with sand. The impure wax melts at a lower temperature and more slowly. What causes this change?  (1 mark)

Two students test ethanol samples. One uses pure ethanol, the other uses ethanol mixed with water. The boiling points are different. Why?  (1 mark)

Two students test ethanol samples. One uses pure ethanol, the other uses ethanol mixed with water. The boiling points are different. Why?  (1 mark)

Two students test ethanol samples. One uses pure ethanol, the other uses ethanol mixed with water. The boiling points are different. Why?  (1 mark)

Two students test ethanol samples. One uses pure ethanol, the other uses ethanol mixed with water. The boiling points are different. Why?  (1 mark)

The diagram below shows boiling points of three water samples: Sample A: Distilled water (100°C), Sample B: Tap water (102°C), Sample C: Salty water (105°C).Which statement best explains the trend in boiling points shown in the diagram?  (1 mark)

The diagram below shows boiling points of three water samples: Sample A: Distilled water (100°C), Sample B: Tap water (102°C), Sample C: Salty water (105°C).Which statement best explains the trend in boiling points shown in the diagram?  (1 mark)

The diagram below shows boiling points of three water samples: Sample A: Distilled water (100°C), Sample B: Tap water (102°C), Sample C: Salty water (105°C). Which statement best explains the trend in boiling points shown in the diagram?  (1 mark)

The diagram below shows boiling points of three water samples: Sample A: Distilled water (100°C), Sample B: Tap water (102°C), Sample C: Salty water (105°C). Which statement best explains the trend in boiling points shown in the diagram?  (1 mark)