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Essential Chemistry for IGCSE - Formulae And Equations (Section 4)

1
Which of the following is a polyatomic ion?
Answer
(C)
SO4^2-
2
Which of the following is the formula for ethanol?
Answer
(B)
C2H5OH
3
What does the term 'oxidation' refer to in a redox reaction?
Answer
(B)
Loss of electrons
4
In a chemical reaction, what is the role of the reactants?
Answer
(B)
They are the starting materials.
5
What is the name of the compound with the formula KNO3?
Answer
(B)
Potassium nitrate
6
What is the meaning of (g) in a chemical reaction?
Answer
(A)
Gas
7
When balancing chemical equations, which of these is essential for the equation to be correctly balanced?
Answer
A
B
D
8
What does the term 'empirical formula' mean?
Answer
(A)
The simplest whole number ratio of atoms in a compound.
9
What is the correct formula for the carbonate ion?
Answer
(B)
CO32-
10
Which of the following is a correct word equation?
Answer
(B)
Sodium + Water -> Sodium hydroxide + Hydrogen
11
Which of the following is the formula for hydrochloric acid?
Answer
(A)
HCl
12
What is the correct formula for calcium oxide?
Answer
(B)
CaO
13
Which compound is formed when hydrogen combines with chlorine?
Answer
(A)
Hydrogen chloride
14
What is the name of the compound whose formula is CO2?
Answer
(B)
Carbon dioxide
15
What is the correct formula for ammonia?
Answer
(A)
NH3
16
What are the products formed when calcium carbonate (CaCO3) is heated?
Answer
(B)
Calcium oxide and carbon dioxide
17
Which of the following is not a diatomic molecule?
Answer
(D)
Helium
18
What is the name of the compound with the formula P4O10?
Answer
(A)
Tetraphosphorus decaoxide
19
What are the reactants in the reaction between zinc and hydrochloric acid?
Answer
(C)
Zinc and hydrochloric acid
20
What is the role of the numbers in the front of the chemical formula, for example, 2H2O?
Answer
(A)
To tell how many molecules are present.
21
What are the products of the complete combustion of propane (C3H8)?
Answer
(B)
Carbon dioxide and water
22
What is the name of the process where a liquid turns into a gas?
Answer
(B)
Boiling
23
Which of the following represents a balanced chemical equation?
Answer
(B)
2H2 + O2 → 2H2O
24
What is the charge of a chloride ion?
Answer
(B)
1-
25
What are the products formed during the reaction of zinc with hydrochloric acid?
Answer
A
B
26
Which of the following is a correct formula for a molecule?
Answer
(B)
H2O
27
Which of the following is the formula for hydrochloric acid?
Answer
(C)
HCl
28
Which of these elements is NOT diatomic?
Answer
(D)
Carbon
29
What type of bond is found in a molecule of oxygen gas (O2)?
Answer
(B)
Covalent bond
30
What is a precipitate in a chemical reaction?
Answer
(B)
A solid that forms and separates from the solution.
31
What does the law of conservation of mass state?
Answer
(C)
Mass is neither created nor destroyed during chemical reactions.
32
Which of the following correctly represents the formula for magnesium chloride?
Answer
(B)
MgCl2
33
What is the meaning of the arrow (→) in a chemical equation?
Answer
(B)
Produces
34
What does the term 'spectator ions' refer to in an ionic equation?
Answer
(A)
Ions that do not participate in the reaction.
35
Which of the following elements are usually found as diatomic molecules?
Answer
A
C
36
What is the formula for sodium carbonate?
Answer
(B)
Na2CO3
37
What is the formula for sulfuric acid?
Answer
(B)
H2SO4
38
What is the state symbol for an aqueous solution?
Answer
(D)
(aq)
39
Which of these elements are diatomic?
Answer
A
C
40
What is the name of the compound with the formula C6H12O6?
Answer
(B)
Glucose
41
What is the name of the compound with the formula C12H22O11?
Answer
(C)
Sucrose
42
What is the balanced chemical equation for the reaction of hydrogen and chlorine to form hydrogen chloride?
Answer
(C)
H2 + Cl2 -> 2HCl
43
Which of the following are elements that exist as diatomic molecules?
Answer
A
B
C
44
What is the name of the compound with the formula Fe2O3?
Answer
(C)
Iron(III) oxide
45
Which of the following statements about the formation of an ionic compound is correct?
Answer
(B)
Atoms gain or lose electrons to achieve a full outer shell.
46
What is the name of the compound with the formula NaCl?
Answer
(A)
Sodium chloride
47
Which of the following is the formula for carbon monoxide?
Answer
(C)
CO
48
What is the chemical symbol for potassium?
Answer
(B)
K
49
Which of the following is the formula for Ozone?
Answer
(C)
O3
50
Which of the following is a correct formula?
Answer
(D)
All of the above