{{asɛmtiNe Ɔkyerɛwfo}} | Nhomakorabea | Nneɛma a ɛma wotumi yɛ ade

1

Sublimation is the process where a substance changes from the liquid to the gaseous state at a definite temperature. (K)

Nokorɛ

Ɛnyɛ ampa

1

Freezing is the process where a substance changes from the solid to the liquid state at a definite temperature. (K)

Nokorɛ

Ɛnyɛ ampa

1

Condensation is the process where a substance changes from the gaseous state to the liquid state at a definite temperature. (K)

Nokorɛ

Ɛnyɛ ampa

1

Which of the following about sea water is NOT true? (K)

Sea water boils at a higher temperature than pure water.

Sea water freezes at lower temperature than pure water.

The boiling point rises as the liquid boils away.

The melting point rises as the liquid freezes.

1

A liquid is called volatile if: (K)

It burns spontaneously in air.

It reacts explosively with oxygen.

It readily evaporates at room temperature.

It boils when heated in air.

1

Which of the following four statements best states how the particles are organized in solid state? (K)

Particles move in all directions and take the shape of the container.

Particles don’t move at all and form definite shape and volume.

Particles vibrate in their position and form definite shape and volume.

Particles move past each other and don’t form definite or volume.

1

At the same temperature, choose which molecules are most likely to have the highest kinetic energy. (K)

Gaseous molecules.

Liquid molecules.

Heaviest molecules.

All have the same average kinetic energy.

1

Inspect the following equation that represents the change of state of a substance, and identify in which changes do the particles gain potential energy. (C)

1&2

2&4

1&3

3&4

1

Gases and liquids have different properties. Interpret the following cases and decide which is true. (C)

50 cm³ of a nitrogen gas has more molecules than 50 cm³ of nitrogen liquid.

Nitrogen gas particles have higher average kinetic energy than Nitrogen liquid particles at the same temperature.

20 g of nitrogen gas occupy more volume than 20 g of nitrogen liquid particles.

Nitrogen gas particles have lower potential energy than Nitrogen liquid particles.

1

Identify which of the following processes causes the most increase of the distance between the particles? (C)

Condensation

Sublimation

Melting

Evaporation

1

The following statements describe the change in kinetic and potential energies of a substance while changing temperature or state.
I. The kinetic energy and potential energy both increase while the substance melts.
II. The potential energy increases while the kinetic energy stays constant while the substance melts.
III. The kinetic energy increases while the potential energy stays constant when the temperature of the substance increases.
IV. The kinetic energy and potential energy both increase when the temperature of the substance increases.
Tell which of the above statement(s) is / are true? (C)

I & IV

II & III

III only

II only

1

Based on the definition of a solution, decide which of the following is Not a solution. (Ap)

Sea water

A steel knife

Air

Liquid mercury

1

The following figure represents a cup of hot coffee. How can the particles of the hot coffee be compared to the particles of air above it? (Ap)

Particles of the hot coffee move faster and are closer together compared to the particles of air above it.

Particles of the hot coffee move faster and are further from each other compared to the particles of air above it.

Particles of the hot coffee move slower and are closer together compared to the particles of air above it.

Particles of the hot coffee move slower and are further from each other compared to the particles of air above it.

1

Inspect the following diagrams and identify which best represents an alloy of copper and zinc knowing that they have the same atomic radius. Type the letter that corresponds to the correct diagram below. (An)

For questions 15-19 use the following diagrams that represent particulate representations of elements compounds and mixtures and choose from below which substance can be represented by each diagram. (An)

Ne gas

H₂O gas

N₂ gas

A gaseous mixture of Ne and N₂

A gaseous mixture of Ne and Xe

A gaseous mixture of N₂, Ne and Xe

A gaseous mixture of Ne and H₂O and N₂

An alloy

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1

Diagram a represents:

1

Diagram b represents:

1

Diagram c represents:

1

Diagram d represents:

1

Diagram e represents:

For questions 20-24 use the diagram below that shows the heating curve of 100g substance X.

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1

What is the boiling point of the substance? (An)

a. - 10 ^oC

20 ^oC

90 ^oC

100 ^oC

1

At what instant does the melting process start? (An)

4 min

7 min

13 min

20 min

1

How long did the vaporization process take? (An)

1.5 min

3 min

3.5 min

7 min

1

What is (are) the state(s) of the substance through the section [CD] of the graph

Solid.

Liquid.

Solid and liquid.

Liquid and gas.

1

On the same graph, sketch the heating curve of a 200 g sample of the same substance between 110^oC and 130^oC. (Syn)

1

A student was handed an unknown homogeneuos solution to test its purity. He measured the boiling point of the substance he found that the substance started boiling at 100^oC and the temperature kept rising till 120^oC. The student claimed that the substance is pure water.
Which of the following best evaluates and justifies the student’s claim? (Ev)

The students claim is correct since water boils at 100 ^oC.

The students claim is correct since water boils at 100 ^oC and the solution is homogeneous.

The students claim is false since the boiling point of this solution was not constant during the experiment.

The student’s claim is false since he must do further experiments to investigate the purity of the solution.

Chemistry test/ Lesson 6

Chemistry test/ Lesson 6

Sublimation is the process where a substance changes from the liquid to the gaseous state at a definite temperature. (K)

Freezing is the process where a substance changes from the solid to the liquid state at a definite temperature. (K)

Condensation is the process where a substance changes from the gaseous state to the liquid state at a definite temperature. (K)

Which of the following about sea water is NOT true? (K)

A liquid is called volatile if: (K)

Which of the following four statements best states how the particles are organized in solid state? (K)

At the same temperature, choose which molecules are most likely to have the highest kinetic energy. (K)

Inspect the following equation that represents the change of state of a substance, and identify in which changes do the particles gain potential energy. (C)

Gases and liquids have different properties. Interpret the following cases and decide which is true. (C)

Identify which of the following processes causes the most increase of the distance between the particles? (C)

Based on the definition of a solution, decide which of the following is Not a solution. (Ap)

The following figure represents a cup of hot coffee. How can the particles of the hot coffee be compared to the particles of air above it? (Ap)

Inspect the following diagrams and identify which best represents an alloy of copper and zinc knowing that they have the same atomic radius. Type the letter that corresponds to the correct diagram below. (An)

Diagram a represents:

Diagram b represents:

Diagram c represents:

Diagram d represents:

Diagram e represents:

What is the boiling point of the substance? (An)

At what instant does the melting process start? (An)

How long did the vaporization process take? (An)

What is (are) the state(s) of the substance through the section [CD] of the graph

On the same graph, sketch the heating curve of a 200 g sample of the same substance between 110oC and 130oC. (Syn)

Sublimation is the process where a substance changes from the liquid to the gaseous state at a definite temperature. (K)

Freezing is the process where a substance changes from the solid to the liquid state at a definite temperature. (K)

Condensation is the process where a substance changes from the gaseous state to the liquid state at a definite temperature. (K)

Which of the following about sea water is NOT true? (K)

A liquid is called volatile if: (K)

Which of the following four statements best states how the particles are organized in solid state? (K)

At the same temperature, choose which molecules are most likely to have the highest kinetic energy. (K)

Inspect the following equation that represents the change of state of a substance, and identify in which changes do the particles gain potential energy. (C)

Gases and liquids have different properties. Interpret the following cases and decide which is true. (C)

Identify which of the following processes causes the most increase of the distance between the particles? (C)

Based on the definition of a solution, decide which of the following is Not a solution. (Ap)

The following figure represents a cup of hot coffee. How can the particles of the hot coffee be compared to the particles of air above it? (Ap)

Inspect the following diagrams and identify which best represents an alloy of copper and zinc knowing that they have the same atomic radius. Type the letter that corresponds to the correct diagram below. (An)

Diagram a represents:

Diagram b represents:

Diagram c represents:

Diagram d represents:

Diagram e represents:

What is the boiling point of the substance? (An)

At what instant does the melting process start? (An)

How long did the vaporization process take? (An)

What is (are) the state(s) of the substance through the section [CD] of the graph

On the same graph, sketch the heating curve of a 200 g sample of the same substance between 110oC and 130oC. (Syn)

On the same graph, sketch the heating curve of a 200 g sample of the same substance between 110^oC and 130^oC. (Syn)

On the same graph, sketch the heating curve of a 200 g sample of the same substance between 110^oC and 130^oC. (Syn)