40 chemistry question for revision

7/30/2019 40 Chemistry question for revision

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1. Which substance is an element?

a) Airb) Steamc) Carbond) Naphthalene

2. What is the meaning of isotopes?a) Atoms of the same element with the

same nucleon number

b) Atoms of the same element withdifferent number of neutrons

c) Atoms of the different elements withdifferent proton numbers

d) Atoms of the different elements withthe same nucleon number

3. Which of the following statements is true for

one mole of a substance?a) 1 mol of copper contain 6.02 X 1023

molecules

b) 1 mol of oxygen gas contains 6.02 X1023 atoms

c) 1 mol of water contains the samenumber of atoms as in 12g of carbon-

12

d) 1 mol of carbon dioxide contains thesame number of molecules as the

number of atoms in 12g of carbon-12

4. The following equation represents a reaction.

Cu(OH)2 (s) + 2HNO3 (aq)

Cu(NO3)2 (aq) + 2H2O (l)

What are the reactants in this equation?

a) Copper(II) nitrate and waterb) Copper(II) nitrate and nitric acidc) Copper(II) hydroxide and nitric acidd) Copper(II) hydroxide and copper(II)

nitrate

5. Which substances are electrolytes?

I. GlucoseII. Acetamide

III. Lead(II)bromideIV. Sodium chloride

a) I and IIb) I and IIIc) II and IVd) III and IV

6. Element M and element L are located in Group 1

and Group 16 in the Periodic Table respectively.

Element M reacts with element L to form a

compound.

What is the chemical formula of the compound?

a) MLb)

ML2

c) M2Ld) M2L3

7. Element J and element Q have proton number of

12 and 9 respectively.

What is the relative formula mass of a

compound formed between J and Q?

[Relative atomic mass : J = 24; Q = 19]

a) 30b) 43c)

62

d) 678. Table 1 show the pH values of four acidic

solutions which have the same concentration.

Solution pH value

K 1.0

L 3.0

M 5.0

N 6.0

Table 1

Which acidic solution has the highest degree ofdissociation?

a) Kb) Lc) Md) N

9. An oxide of element X has the empirical formula

of X2O3. 2.24 g of element X reacts completely

with 0.96 g of oxygen.

What is the relative atomic mass of X?

[Relative atomic mass : O = 16 ]a) 112b) 56c) 25d) 17

10. Which substance is an ionic compound?

a) Ethanol, C2H5OHb) Sulphur dioxide, SO2c) Tetrachloromethane, CCl4d) Magnesium oxide, MgO


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11. Table 2 shows two elements and their

respective relative atomic mass.

The letters used are not the actual symbol of

the elements.

Element Relative atomic

mass

X 24M 12

Table 2

Which of the following is true about the atoms

of element X and M?

a) The mass of 1 mol of X is twice themass of 1 mol of M

b) 1 mol of X has the same mass as 1 molof M

c) The mass of an atom of X is 24g andthe mass of an atom of M is 12g

d) The number of mole in 12g of atom Xis equal to the number of mole in 12gof atom M

12. The empirical formula of copper oxide is

determined by its reaction with hydrogen.

The heating, cooling or weighing steps are

repeated several times but a constant mass of

the product is still not obtained.

Which of the following can be done to get a

constant mass of the product?

a)

During heating, dry hydrogen gas ispassed through

b) During cooling, dry hydrogen gas ispassed through

c) During weighing, the combustion tubemust be stoppered

d) During heating, excess hydrogen gas isburnt

13. Which of the following substances is acidic?

a) Ammoniab)

Potassium oxide

c) Carbon dioxided) Sodium hydroxide

14. Which of the following is true about

electrolytes?

a) Elements that conduct electricity inmolten state

b) Compound that conduct electricity insolid state

c) Elements that conduct electricity insolid or molten state

d) Compounds that conduct electricity inmolten state or aqueous solution

15. Which statement explains why the size of the

atoms of Group 1 elements increases when

going down the group in the Periodic Table?

a) The number of protons increasesb) The relative atomic mass increasesc) The number of valence electrons

increasesd) The number of shells with electrons

increases

16. The following equation shows the

decomposition of hydrogen peroxide, H2O2.

2 H2O2 (l) 2H2O (l) + O2 (g)

What is the volume of oxygen gas, O2 produced

from the decomposition of 500 cm3 of 2 mol

dm-3 hydrogen peroxide at standard

temperature and pressure (STP)?

[Molar volume of gas at STP = 22.4 dm3

mol-1

]a) 11.2 dm3b) 22.4 dm3c) 33.6 dm3d) 44.8 dm3

17. Which element can form acidic oxides?

I. MagnesiumII. Sulphur

III. SodiumIV. Phosphorus

a) I and IIb) I and IIIc) II and IVd) III and IV

18. Metal X has the following properties.

Less reactive than iron Does not react with iron(III)oxide

Which metal oxide can react with X?

a) Zinc oxideb) Magnesium oxidec)

Copper(II)oxide

d) Aluminium oxide19. Which substance is a covalent compound?

a) Phosphorus(V)oxideb) Sodium sulphatec) Magnesium chlorided) Lead(II)chloride


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20. Which statement explains why the reactivity of

Group 1 elements increases when going down

the group?

a) The physical state of the elementschanges from gas to liquid then to

solid at room temperature

b)

The attractive force between valenceelectron and the nucleus becomes

stronger

c) The valence electron gets further awayfrom the nucleus

d) The melting point of the elementsdecrease

21. Table 3 shows the property of elements P, Q

and R. These elements are located in the

same period in the Periodic Table.

Element Property of oxideP Acidic

Q Basic

R Amphoteric

Table 3

Arrange the three elements based on the

increasing of proton number.

a) R, Q, Pb) R, P, Qc) Q, P, Rd) Q, R, P

22. Table 4 shows the electron arrangements of

atoms P, Q, R and S.

Atom Electron

arrangement

P 2.4

Q 2.8.1

R 2.8.2

S 2.8.7

Table 4

Which pair of atoms forms a compound by

sharing electrons?a) P and Sb) P and Rc) Q and Sd) Q and R

23. Which of the following is a property of

potassium fluoride?

a) Volatileb) Insoluble in waterc) Has a low melting pointd) Conducts electricity in the molten

state

24. Table 5 shows information about three voltaic cells.

Metals X, Y and Z are used as electrodes in the cells.

Voltaic

cell

Negative

terminal

Positive

terminal

Voltage

(V)

I X Y 3.0

II Z Y 1.2

III X Z 1.8Table 5

What is the order of the metals from the most

electropositive to the least electropositive?

a) X, Y, Zb) X, Z, Yc) Y, Z, Xd) Z, X, Y

25. Table 6 shows the positive terminal and voltmeter

readings of three pairs of metals used as electrodes in

voltaic cells.Pair of

metal

Positive

terminal

Voltmeter

reading (V)

R, S S 1.8

S, Q S 0.3

P, R R 0.2

Table 6

What is the voltmeter reading when P and Q are the

pair of metals used as electrodes?

a) 0.1Vb) 0.5Vc) 1.7Vd) 2.3V

26. Which electrolyte and electrodes can be used to purify

copper?

Electrolyte Electrode

Anode Cathode

a) Copper(II)sulphate

solution

Pure

copper

Impure

copper

b) Copper(II)nitrate

solution

Impure

copper

Pure

copper

c) Sulphuric acid Purecopper

Impurecopper

d) Nitric acid Impure

copper

Pure

copper

27. Which of the following conatins 6.02 X 1023 atoms?

a) 1 mol of nitrogen gasb) 1 mol of chlorine gasc) 1 mol of ammoniad) 1 mol of neon


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28. Which of the following is not a chemical

property of acids?

a) Reacts with carbonate to produce salt,water and carbon dioxide

b) Reacts with reactive metal to producesalt and hydrogen

c)

Reacts with metal oxide to producesalt and water

d) Reacts with alkali to produce salt andhydrogen

29. 0.1 mol dm-3 solution of X has a pH value of 13.

Which statement is correct about the solution?

a) X is a weak acidb) X is a strong alkalic) X dissociates partially in waterd) X has a high concentration of

hydrogen ions

30. Table 7 shows the proton numbers of elements

X and Y. X and Y are not the actual symbols of

the elements.

Element Proton

number

X 11

Y 19

Table 7

Which statements are true about elements X

and Y?I. Atoms X and Y have one valence

electron

II. Element X is more reactive thanelement Y

III. Atom X has a bigger atomic size thanatom Y

IV. Elements X and Y are in the samegroup in the Periodic Table

a) I and IIIb)

I and IV

c) II and IIId) II and IV

31. Alkali Y of concentration 1 mol dm-3 has a pH of

13.

Which statement is true about alkali Y?

a) Slightly soluble in waterb) Reacts only with a weak acidc) The degree of ionization in water is

high

d)

Has a low concentration of hydroxideions

32. Table 8 shows the electron arrangement for

elements W, X, Y and Z.

The letters used are not the actual symbol of

the elements.

Element Electron

arrangement

W 2.1X 2.3

Y 2.8.3

Z 2.8.7

Table 8

Which of the following is an element of Period

3 and able to form an amphoteric oxide?

a) Wb) Xc) Yd) Z

33. Element T has the same chemical property as

the element with the proton number of 20.

The letter T is not the actual symbol of the

element.

Which of the following is the electron

arrangement for an atom of element T?

a) 2b) 2.8.2c) 2.8.4d) 2.8.8

34. What is the number of moles of copper (II)

nitrate in 56.4g of copper (II) nitrate,

Cu(NO3)2?

[Relative atomic mass : O = 16, Cu = 64, N = 14]

a) 0.30 molb) 0.32 molc) 0.45 mold) 3.33 mol

35. The following equation represents the

neutralization reaction between bariumhydroxide, Ba(OH)2 and hydrochloric acid, HCl.

Ba(OH)2 + 2HCl BaCl2 + 2H2O

What is the volume of 0.5 mol dm-3

hydrochloric acid needed to neutralize 25 cm3

of 0.1 mol dm-3 barium hydroxide?

a) 2.5 cm3b) 5.0 cm3c) 10.0 cm3d) 12.5 cm3


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36. The chemical formula for potassium

hexacyanoferrate (III) is K3Fe(CN)6.

What is its relative formula mass?

[Relative atomic mass of C = 12, N = 14, K = 39

and Fe = 56]

a) 121b)

199

c) 251d) 329

37. If the Avogadro number is represented by the

letter x, what is the number of hydrogen gas

particles, H2, with the molar volume of 24 dm3

mol-1 at room temperature and pressure?

a) xb) 2xc) x2d)

1/2x

38. The mass of three atoms of element X is equal

to the mass of four carbon atoms. X is not the

actual symbol of the element.

What is relative atomic mass of element X?

[Relative atomic mass : C = 12]

a) 48b) 36c) 16d) 12

39. A dibase acid, H2J has the concentration of 0.5

mol dm-3.

Letter J is not the actual symbol of the element.

What is the volume of potassium hydroxide,

KOH, 1.0 mol dm-3 that can neutralize 25.0 cm3

of the H2J acid solution?

a) 6.25 cm3b) 12.50 cm3c) 25.00 cm3d) 50.00 cm3

40. Sodium reacts with chlorine to form sodium

chloride.

2Na + Cl2 2NaCl

What is the mass of sodium chloride formed

when 2.30g of sodium reacts with excess

chlorine?

[Relative atomic mass : Na = 23, Cl = 35.5]

a) 2.93 gb) 3.85 gc) 9.40 gd) 11.70 g

40 chemistry question for revision

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