ข้อสอบ TBAT Chemistry พร้อมเฉลย สำหรับเตรียมความพร้อมก่อนสอบ

01. The diagram shows the result of dropping a purple crystal into water.

Which processes take place in this experiment?

tbat chemistry q01

A) Answer B

B) Answer C

C) Answer A

D) Answer D

02. Which row about elements, mixtures and compounds is correct?

tbat chemistry q02

A) Answer C

B) Answer A

C) Answer B

D) Answer D

03. What are the relative charge and relative mass of an electron?

A) Answer A

B) Answer C

C) Answer D

D) Answer B

04. The atomic structures of four particles, W, X, Y and Z, are shown.

Which particles are isotopes of the same element?

tbat chemistry q04

A) X and Z

B) W and Y

C) X and Y

D) W and X

05. Which row shows the properties of an ionic compound ?

tbat chemistry q05

A) Answer D

B) Answer A

C) Answer C

D) Answer B

06. Which row describes the formation of single covalent bonds in methane?

tbat chemistry q06

A) Answer C

B) Answer B

C) Answer A

D) Answer D

07. Which equation represents the neutralisation of nitric acid using sodium hydroxide?

A) NaOH(aq) + HNO₃(aq) -> NaNO₃(aq) + H₂O(I)

B) NaOH(I) + HNO₃(I) -> NaNO₃(I) + H₂O(aq)

C) NaOH(I) + HNO₃(aq) -> NaNO₃(I) + H₂O(I)

D) NaOH(I) + HNO₃(I) -> NaNO₃(I) + H₂O(I)

08. What is the relative formula mass of ammonium nitrate, NH₄NO₃ ?

A) 108

B) 80

C) 122

D) 150

09. Concentrated aqueous sodium chloride is electrolysed using inert electrodes. Gases X and Y are produced at the electrodes shown.

What are X and Y ?

tbat chemistry q09

A) Answer B

B) Answer C

C) Answer D

D) Answer A

10. Which statement about hydrogen fuel cells is correct?

A) The reaction in a fuel cell is endothermic.

B) Hydrogen fuel cells do not produce carbon dioxide.

C) The waste from a hydrogen fuel cell is an acidic gas.

D) Hydrogen fuel cells do not need oxygen.

11. A reaction pathway diagram is shown.

tbat chemistry q11

A) The reaction is endothermic.

B) The temperature of the surroundings increases.

C) The reaction rate increases during the reaction.

D) The reaction transfers thermal energy to the surroundings.

12. Lumps of calcium carbonate react with dilute hydrochloric acid as shown.

CaCO₃ + 2HC/ -> CaC/₂ + H₂O + CO₂

Which change in conditions decreases the rate of the reaction ?

A) increasing the concentration of the acid

B) increasing the temperature

C) increasing the size of the lumps of calcium carbonate

D) increasing the volume of the acid

13. Solid copper (II) sulfate exists in two different forms, anhydrous and hydrated.

One of these forms is blue and the other is white.

The change between these two forms is reversible.

blue form ⇌ white form

What is the blue form and how is the change from the blue form to the white form brought about ?

tbat chemistry ข้อ 13

A) Answer D

B) Answer A

C) Answer C

D) Answer B

14. Four redox equations and statements about the equations are shown.

Which statements about the equations are correct?

tbat chemistry q14

A) 1 and 2

B) 1 and 3

C) 3 and 4

D) 2 and 4

15. Sodium hydroxide forms an alkaline solution with a pH of 14.
Which indicator turns yellow when added to this solution?

A) thymolphthalein

B) methyl orange

C) litmus

D) universal indicator

16. Which row identifies an acidic oxide and a basic oxide?

A) Answer A

B) Answer B

C) Answer D

D) Answer C

17. A Student makes aqueous copper (II) chloride by adding excess copper (II) carbonate to dilute hydrochloric acid. What is the next step in the method in the formation of solid copper (II) chloride ?

A) titration

B) evaporation

C) crystallisation

D) filtration

18. Which statements about the trends across a period of the Periodic Table are correct ?

luminium is more metallic than sodium.
Beryllium is more metallic than carbon.
Boron is more metallic than lithium.
Magnesium is more metallic than silicon.

A) 1 and 3

B) 3 and 4

C) 1 and 2

D) 2 and 4

19. Which row shows the trend in melting point, density and reactivity as Group is descended?

tbat chemistry q19

A) Answer A

B) Answer D

C) Answer B

D) Answer C

20. Which row describes a similarity and a difference between chlorine and bromine?

tbat chemistry q20

A) Answer C

B) Answer A

C) Answer B

D) Answer D

21. Which statement describes transition elements ?

A) They have high densities and low melting points.

B) They have high densities and high melting points.

C) They have low densities and low melting points.

D) They have low densities and high melting points.

22. Which diagram shows the electric structure of a noble gas ?

tbat chemistry q22

A) Answer A

B) Answer C

C) Answer D

D) Answer B

23. Which gas is made when powdered zinc is added to dilute hydrochloric acid ?

A) chlorine

B) oxygen

C) carbon dioxide

D) hydrogen

24. Which metal is used in aircraft manufacture because it has a low density ?

A) potassium

B) copper

C) aluminium

D) iron

25. The diagram represents the structure of a solid.

Which solids does the diagram represent ?

tbat chemistry q25

A) Answer D

B) Answer C

C) Answer B

D) Answer A

26. Three students, X, Y and Z, are told that solid P reacts with dilute acids and also conducts electricity.

The table shows the students’ suggestions about the identity of P.

Which students are correct ?

tbat chemistry q26

A) X, Y and Z

B) X only

C) Z only

D) Y only

27. Which substances in the air are needed for iron to rust ?

A) water and carbon dioxide

B) oxygen only

C) water only

D) oxygen and water

28. Part of the reactivity series of metals is shown.

tbat chemistry q28

A) Answer C

B) Answer A

C) Answer B

D) Answer D

29. Which gas has the fastest rate of diffusion?

A) HC/

B) Ar

C) H₂S

D) C₂H₆

30. There are two stable isotopes of bromine.

    The mass number of isotope 1 is 79.

    The mass number of isotope 2 is 81.

    Which statement is correct ?

A) The isotopes have the same number of outer electrons.

B) The isotopes have different chemical properties.

C) The isotopes have different numbers of protons.

D) The isotopes have the same number of neutrons.

31. Which statement about ions and ionic bonds is correct ?

A) Positive ions are formed when atoms lose protons.

B) Bromine atoms form negatively charged bromide ions.

C) Potassium iodide contains negatively charged potassium ions.

D) Ionic bonds form between elements in Group VII of the Periodic Table.

32. Part of the Periodic Table is shown.

Which type of chemical bonding is present in the oxide of F and in the oxide of G?

tbat chemistry q32

A) Answer D

B) Answer B

C) Answer C

D) Answer A

33. Elements X and Y react to form a compound.

Element X loses two electrons and element Y gains one electron.

What is the charge on the ions of elements X and Y and what is the formula of the compound ?

tbat chemistry ข้อ 33

A) Answer B

B) Answer D

C) Answer A

D) Answer C

34. Which statement about graphite explains why it is used as an electrode ?

A) It has a giant covalent structure.

B) It contains ions.

C) It has mobile electrons.

D) It is a metal.

35. Methane, CH₄, burns in air to form carbon dioxide and water.

What is the balanced equation for this reaction ?

A) CH₄(g) + 2O₂(g) -> CO₂(g) + H₂O(g)

B) CH₄(g) + 3O₂(g) -> CO₂(g) + 2H₂O(g)

C) CH₄(g) + O₂(g) -> CO₂(g) + 2H₂O(g)

D) CH₄(g) + 2O₂(g) -> CO₂(g) + 2H₂O(g)

36. The equation for the thermal decomposition of sodium hydrogen carbonate is shown.

2NaHCO₃ -> Na₂CO₃ + H₂O + CO₂

The M_r of sodium hydrogen carbonate, NaHCO₃, is 84.

The Mr of sodium carbonate, Na₂CO₃, is 106.

In an experiment, 2.1 g of sodium hydrogencarbonate is heated but not all of it decomposes. All of the carbon dioxide is collected and measured at room temperature and pressure. The total volume of carbon dioxide produced is 0.21 dm³.

The volume of 1 mole of a gas at room temperature and pressure is 24 dm³.

Which statement is correct ?

A) The percentage yield of carbon dioxide is 35%.

B) The mass of sodium carbonate produced is 1.33 g.

C) The mass of sodium carbonate produced is 0.93 g.

D) The percentage yield of carbon dioxide is 10%.

37. An electrolysis experiment is done using carbon electrodes.

Hydrogen and oxygen are formed at the electrodes.

What is the electrolyte ?

A) aqueous copper(II) sulfate

B) concentrated hydrochloric acid

C) dilute aqueous sodium chloride

D) molten potassium oxide

38. Concentrated aqueous copper(II) sulfate is electrolysed using copper electrodes.

Which ionic half-equation describes the reaction taking place at the cathode ?

A) 4OH^- -> O₂ + 2H₂O + 4e^-

B) Cu²⁺ + 2e^- -> Cu

C) 2H⁺ + 2e^- -> H_-

D) Cu -> Cu²⁺ + 2e^-

39. When powdered sodium carbonate and aqueous ethanoic acid are mixed, the temperature of the mixture falls.

Which statement about this reaction is correct ?

A) The reaction is endothermic and ∆H is positive.

B) The reaction is exothermic and ∆H is positive.

C) The reaction is endothermic and ∆H is negative.

D) The reaction is exothermic and ∆H is negative.

40. Magnesium powder reacts with an excess of dilute hydrochloric acid to produce hydrogen gas.

Which statement about this reaction are correct ?

The smaller the particles of magnesium powder, the more slowly the hydrogen is produced.
The higher the temperature, the faster the magnesium powder disappears.
The lower the concentration of dilute hydrochloric acid, the faster the rate of reaction.
The faster the magnesium powder disappears, the faster the rate of reaction.

A) 3 and 4

B) 2 and 3

C) 1 and 2

D) 2 and 4

41. The reaction between two aqueous compounds, X and Y, is slow and exothermic.

The graph shows how the rate of this reaction changes with time.

A student suggests that the rate of reaction decreases with time because:

the activation energy decreases.
the speed of the molecules of X and Y decreases.
the concentration of both X and Y decreases with time.

Which suggestions are correct ?

TBAT Chemistry-ข้อ 41

A) 1 and 2

B) 1 and 3

C) 3 only

D) 2 only

42. Hydrogen reacts with iodine to form hydrogen iodide.

H₂(g) + I₂(g) -> 2HI(g)

Which statements explain why the reaction is faster when the pressure is increased, at constant temperature ?

At higher pressure, the molecules are moving faster.
At higher pressure, more of the molecules have the required activation energy.
At higher pressure, the molecules are closer together.
At higher pressure, the molecules collide more frequently.

A) 1 and 3

B) 2 and 4

C) 3 and 4

D) 1 and 2

43. Ammonium sulfate is used as a fertiliser.

It is made from ammonia and slfuric acid.

The …1… is made by the …2… process in which …3… is used as a catalyst.

Which words complete gaps 1, 2 and 3 ?

tbat chemistry ข้อ 43

A) Answer D

B) Answer B

C) Answer C

D) Answer D

44. The reversible reaction shown takes place in a closed system at constant temperature.

P(g) + Q(g) + R(g) ⇌ S(g) + T(g)

When the reaction has reached equilibrium, more T is added.

After the addition of T, which other substances increase in concentration ?

A) P, Q and R only

B) S only

C) P, Q, R and S

D) P and Q only

45. In which equation is the underlined substance acting as a reducing agent ?

A) 3CO + Fe²O³ -> 2Fe + 3CO₂

B) CuO + H₂ -> Cu + H₂O

C) CO₂ + C -> 2CO

D) CaO + H₂O -> Ca(OH)₂

46. An aqueous solution reacts with a solid. The products are an alkaline gas, a salt and water.

What are the aqueous solution and the solid ?

tbat chemistry q46

A) Answer D

B) Answer B

C) Answer A

D) Answer C

47. Butanoic acid partially dissociates in aqueous solution.

Which row about butanoic acid is correct ?

Copper(II) sulfate is prepared by adding excess copper(II) carbonate to sulfuric acid.

Why is an excess of copper(II) carbonate added ?

tbat chemistry q47

A) to increase the rate of reaction

B) to ensure all the copper(II) carbonate has reacted

C) to increase the amount of copper(II) sulfate produced

D) to ensure all the sulfuric acid has reacted

48. Part of the Periodic Table is shown.

Which element has two electrons in its outer shell and three electron shells ?

tbat chemistry q48

A) Answer B

B) Answer C

C) Answer A

D) Answer D

49. Elements in Group I and Group II show the same trends in their reactions with water and in their density.

Which row shows how the properties of barium compare with calcium ?