Structure of Atoms

MCQ – Particulat Nature of Matter

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Questions

  1. Which of the following statements is not true?
    1. Matter is anything that occupies space and has mass.
    2. The particle theory of matter states that matter is made up of a large number of tiny and discrete particles.
    3. The kinetic energy of the particles in a matter increases if its temperature increases.
    4. The particles in all kind of matter are identical.
  2. Which of the following shows the correct comparison of the average kinetic energy of the particles in a solid, liquid and gas for a given substance?
    1. Solid > Liquid > Gas
    2. Solid < Liquid < Gas
    3. Solid = Liquid = Gas
    4. It depends on what kind of substance it is.
  3. The diagram shows the arrangement of particles in a substance. Which of the following is not the characteristic of the substance in this state?
    1. Particles move randomly and slowly and sometimes will collide against each other.
    2. The volume of the object is not fixed.
    3. Particles are not arranged in order. Most of the particles are still in contact with one another.
    4. Difficult to be compressed.
  4. Which of the following statements is not true about the particles in a gas?
    1. The particles of gas move at high speed
    2. The collision between the gas particles and the wall of the container is elastic.
    3. The gas particles move randomly in all direction.
    4. The gas particles are arranged in regular patterns.
  5. Which of the following take place when water solidifies to become ice?
    1. Water molecules get nearer to each other.
    2. Energy is absorbed from the surrounding.
    3. Water molecules are not arranged orderly.
    4. The mass increase.
  6. Which of the following substances sublimes at room pressure when heated?
    1. Iodine
    2. Dry ice (Solid carbon dioxide)
    3. Naphthalene
    4. Ammonium Chloride
  7. The particle theory of matter states that
    Matter is made up of a large number of tiny and discrete particles.
    Which of the following phenomenon does not support this hypothesis?
    1. Brownian Motion
    2. The shape of a solid is fixed.
    3. Diffusion of bromine vapour in gas.
    4. The volume of a substance increase when it transforms from a liquid into gas.

Take the Test

[WpProQuiz 3]

Three States of Matter – Structured Question 4

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Structure Question 4:
Figure (a)
Figure (b)

Figure (a) shows the set-up of the apparatus to investigate the heating process of substance Y. In this experiment, solid substance Y was heated in a water bath from room temperature until it turned into gas. Substance Y was stirred throughout the whole experiment. The temperature of substance Y was recorded at fixed intervals of time and the graph of temperature against time during the heating of substance Y is shown in Figure (b) above.

Answer:

  1. What is the physical state of naphthalene at the region
    1. QR
      solid and liquid
    2. ST
      liquid and gas
    3. TU
      Gas only
  2. What is the time when substance Y begins to melt?[1 mark]

    t1
  3. What is the boiling point of substance Y?[1 mark]
    95°C
  4. Why the temperature of M remains unchanged from time t3 to t2 even though heating continues?
    From t1 to t2, substance Y is melting. The heat supply to the substance is used to overcome the strong attraction force between the solid particles. No heat energy is used to increase the kinetic energy (temperature) of the particles.
  5. Why water bath is used for heating the solid of substance Y?To ensure uniform heating on substance-Y
  6. Give a reason why water bath is suitable in this experiment?Because the melting point and boiling point of substance Y is lower than the boiling point of water.
  7. Name 2 substance, whose boiling point can be determined by using water bath.
    Alcohol and ether
  8. Given that the boiling point of substance X is around 105°C. Why can’t we use water bath to determine the boiling point of substance Y?The boiling point of water is 100°C, which means the maximum temperature that can be achieved by water is 100°C, which is lower than the boiling point of substance-X.
    Substance X can not be boiled by using water bath.
  9. Suggest another method which can replace water bath in this experiment.Use oil bath or sand bath instead of water bath.
  10. Why stirring of substance Y is required throughout the whole experiment?So that heat is spread evenly throughout the substance.
  11. Compare the kinetic energy of particles of substance Y at t1 and t3.The kinetic energy of particles at t3 is higher than the kinetic energy of particles at t1.
  12. State one different in the arrangement of the particles of substance Y before t1 and after t4.Before t1, particles are arrange in an orderly manner and close to one another. After t4, the particles are very far apart and randomly arrange.

Three States of Matter – Structured Question 3

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Structure Question 3:
The table below shows the melting and boiling points of three different substances.

Substance
Melting Point
Boiling Point
H
-120°C
-5°C
I
45°C
98°C
J
10°C
350°C

Answer:

  1. What is the physical state of H, I and J at room temperature (25°C)?
    H: gaseous I: solid J: liquid
  2. Which substance diffuses the fastest at room temperature? Explain your answer.
    Substance H. Because substance H exist as a gas at room temperature, hence there is a lot of empty space between the particles. Other than that, the particles of H have the highest kinetic energy.
  3. Draw some diagrams to show the arrangement of particles of substance I at 40°C, 80°C and 120°C.At 40°C

    At 80°C

    At 120°C

  4. What is the name of the process which atoms or molecules of a substance in liquid state gain sufficient energy to enter the gaseous state below boiling point?
    Evaporation
  5. Define boiling point.
    Boiling Point is the temperature at which the pressure exerted by the surroundings upon a liquid is equalled by the pressure exerted by the vapour of the liquid.
  6. Sketch the graph of temperature against time for substance I when it is cooled from 120°C to room temperature.

Three States of Matter – Structured Question 2

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Structure Question 2:

An experiment is conducted to study the change of state of iodine. Some powder of solid iodine is heated as shown in the Figure above, the black solid iodine changes into a purple gas at 125°C. The purple gas is then cooled by a round bottom flask that fill with ice.

Answer:

  1. State the process of change of state demonstrated by iodine at 125°C.
    Sublimation
  2. What can be observed at part R?

    Some black powder form at the bottom of the flask.

  3. What is the name of the process when iodine gas turns into iodine solid again?

    Reverse/inverse sublimation

  4. Explain why palm oil is used in the experiment instead of water.

    Because iodine sublime at 125°C, the temperature which is higher than the boiling point of water.

  5. Name two other substances which also sublime at atmospheric pressure (1atm).

    Ammonium chloride, carbon dioxide, naphthalene.

Three States of Matter – Structured Question 1

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Structure Question 1:

The above diagram shows the apparatus used in an experiment to determine the freezing point of liquid naphthalene. The liquid naphthalene is cooled from 100°C in a conical flask and it is stirred continuously with a thermometer. The temperature of liquid naphthalene is recorded in every 30 seconds. The results obtained are tabulated below:

Time (s)0306090120150
Temperature (oC)1009385787878
Time (s)180210240270300
Temperature (oC)7860432525

Answer:

  1. Draw a graph of temperature against time for the cooling of liquid naphthalene. [2 marks]
    (Click on the image to enlarge)
  2. Determine the freezing point of liquid naphthalene from the graph.
    78°C
  3. c.What is the physical state of naphthalene at
    1. 60s
      liquid
    2. 120s
      liquid and solid
    3. 180s
      solid
  4. Draw the particles arrangement of naphthalene at c.i. and  c.iiic. i.

    c. ii.

  5. Explain why the temperature remains constant between 3 and 6 minutes?
    From the time 90 second to 180 seconds, naphthalene is freezing. During freezing, bonds are formed in between the molecules and energy is released. The energy lost to the surrounding is compensated by the energy released from the formation of the bonds.
  6. Explain why the boiling tube is placed inside a conical flask during the cooling process.
    To ensure constant cooling at a slow rate for naphthalene. This can avoid supercooling.
  7. Give a reason why naphthalene needs to be stirred continuously during the process?
    To avoid supercooling.
  8. Will the melting point of naphthalene differ if it is contaminated by other substance?
    Yes
  9. Sketch a graph obtained when solid naphthalene is heated from room temperature (25°C) to 100°C.

Objective Question s Practice 1

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  1. Which of the following substances sublimes at room pressure when heated?
    1. Iodine
    2. Dry ice (Solid carbon dioxide)
    3. Naphthalene
    4. Ammonium Chloride
  2. Which of the following take place when water solidifies to become ice?
    1. Energy is absorbed from the surrounding.
    2. Water molecules get nearer to each other.
    3. Water molecules are not arranged orderly.
    4. The mass increase.

Symbol of Element

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Symbol of Elements

A symbol of element is the chemical symbol written in short form to represent a particular element. Some elements are represented by the first letter of its name.

Examples:

Element Symbol
Fluorine F
Hydrogen H
Iodine I
Nitrogen N
Oxygen O
Phosphorus P
Sulphur S
Carbon C
Vanadium V

If there are two or more elements that have mane start with the same alphabet letter, a second letter is added to differentiate between these elements. The second letter used is always lowercase.
Examples:

Elements Symbol
Bromine Br
Calcium Ca
Chlorine Cl
Chromium Cr
Magnesium Mg
Manganese Mn
Neon Ne
Nickel Ni
Silicon Si
Helium He
Argon Ar
Aluminium Al
Zinc Zn
Platinum Pt

Some elements are represented by their Latin names.
Example:

Elements Latin Name Symbol
Copper Cuprum
Cu
Iron Ferrum
Fe
Lead Plumbum
Pb
Mercury Hydrargyrum
Hg
Potassium Kalium
K
Silver Argentum
Ag
Sodium Natrium
Na
Tin Stannum
Sn

(Notes: You MUST Memorise the symbol for all these 31 elements)

Brownian Motion

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Brownian Motion

  1. Brownian motion is the physical phenomenon that tiny particles immersed in a fluid move about randomly.
  2. A fluid can be a liquid or a gas.
  3. Brownian movement, an example of diffusion, supports the kinetic theory of matter.
  4. Examples of Brownian movement are
    1. movement of smoke particles in air
    2. movement of pollen grains in water

Interesting Video - Brownian Motion

Diffusion in Gas

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Diffusion in Gas

(Diffusion in Gas)
Observation

The brown colour bromine vapour spreads evenly throughout the gas jar in a few minutes

  • Bromine vapour is made of tiny and discrete molecules that move randomly to fill up space.
  • Bromine vapour moves randomly and diffuses in all directions in air from areas of higher concentration to areas of lower concentration.
Conclusion :
The rate of diffusion is highest in gas and lowest in solid.

Diffusion in Liquid

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Diffusion in Liquid

(Diffusion in Liquid)
Observation
The purple colour of potassium manganate(VII) fills up the entire test tube after a few hours
  • Diffusion has taken place in the liquid.
  • The rate of diffusion of the particles in water is faster than the diffusion rate of particles in solid.
  • The occurrence of diffusion proves that potassium permanganate(VII) consist of tiny and discrete particles.