Chemistry test/ Lesson 6

Last updated over 5 years ago

25 questions

1

Library

Chemistry test/ Lesson 6

Last updated over 5 years ago

25 questions

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

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.

1

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

1

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

True

False

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

True

False

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

True

False

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.

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.

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.

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.

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

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.

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

Condensation

Sublimation

Melting

Evaporation

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

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

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.

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

Diagram a represents:

Diagram b represents:

Diagram c represents:

Diagram d represents:

Diagram e represents:

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

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

a. - 10 oC

20 oC

90 oC

100 oC

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

4 min

7 min

13 min

20 min

How long did the vaporization process take? (An)

1.5 min

3 min

3.5 min

7 min

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

Solid.

Liquid.

Solid and liquid.

Liquid and gas.

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

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 100oC and the temperature kept rising till 120oC. 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.

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

True

False

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

True

False

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

True

False

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.

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.

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.

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.

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

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.

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

Condensation

Sublimation

Melting

Evaporation

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

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

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.

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

a. - 10 oC

20 oC

90 oC

100 oC

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

4 min

7 min

13 min

20 min

How long did the vaporization process take? (An)

1.5 min

3 min

3.5 min

7 min

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

Solid.

Liquid.

Solid and liquid.

Liquid and gas.

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 100oC and the temperature kept rising till 120oC. 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.