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Essential Chemistry for IGCSE - Formulae And Equations (Section 3)

1
What is the formula for sulfuric acid?
Answer
(B)
H2SO4
2
Which of the following are examples of a diatomic element?
Answer
(B)
Hydrogen
3
What is the chemical formula for methane?
Answer
(A)
CH4
4
What are the products when zinc reacts with hydrochloric acid?
Answer
(A)
Zinc chloride and hydrogen
5
What is the formula for ammonium chloride?
Answer
(B)
NH4Cl
6
Which of the following represent a balanced chemical equation?
Answer
(D)
2H2 + O2 -> 2H2O
7
What does the term (aq) represent in a chemical equation?
Answer
(D)
Aqueous solution (dissolved in water)
8
What is a substance that releases hydrogen ions (H+) in water?
Answer
(C)
An acid
9
What does the term 'empirical formula' represent?
Answer
(B)
The simplest whole-number ratio of atoms in a compound
10
What does the term 'diatomic' mean in chemistry?
Answer
(A)
Two atoms of the same element bonded together
11
In the equation: Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g), identify all the state symbols used:
Answer
A
C
D
12
What is the process called when an acid reacts with a base to produce salt and water?
Answer
(C)
Neutralization
13
Which of these is a correct way to write a state symbol in an equation?
Answer
A
C
14
Which of the following are required to balance chemical equations?
Answer
A
C
D
15
What is the valency of oxygen?
Answer
(B)
2
16
Which of the following are examples of chemical reactions?
Answer
A
C
17
Which of the following equations is correctly balanced?
Answer
(C)
2H2 + O2 -> 2H2O
18
Which of the following is the formula for potassium oxide?
Answer
(B)
K2O
19
What is the name of the compound with the formula KNO3?
Answer
(A)
Potassium nitrate
20
Which of the following is a characteristic of a base?
Answer
(D)
Feels slippery.
21
What is the chemical symbol for copper?
Answer
(B)
Cu
22
Which of the following is an example of an acid?
Answer
(B)
HCl
23
Which of the following is the formula for a base?
Answer
(C)
NaOH
24
What is the charge of a hydroxide ion?
Answer
(A)
1-
25
What is the role of a catalyst in a chemical reaction?
Answer
(C)
To speed up the rate of reaction.
26
What is the product of the reaction between sodium and water?
Answer
(A)
Sodium hydroxide and hydrogen gas
27
Which of the following is a correct way to write a symbol equation?
Answer
(B)
Na + Cl -> NaCl
28
What is the formula for sodium hydroxide?
Answer
(B)
NaOH
29
Which of the following is the correct formula for ammonium chloride?
Answer
(A)
NH4Cl
30
What does the symbol (s) next to a chemical formula represent?
Answer
(A)
Solid
31
Which of the following is the correct formula for carbon dioxide?
Answer
(B)
CO2
32
What does (aq) indicate in a chemical equation?
Answer
(A)
Aqueous
33
What is the chemical symbol for gold?
Answer
(C)
Au
34
What is the name of the following compound: K2O?
Answer
(A)
Potassium oxide
35
What does the term 'mole' represent in chemistry?
Answer
(C)
A unit of amount of substance
36
What is the charge on an oxide ion?
Answer
(B)
2-
37
What is a word equation used for?
Answer
(B)
To describe the reactants and products of a chemical reaction in words.
38
Which of the following is a correct chemical equation?
Answer
(B)
2H2 + O2 -> 2H2O
39
Which of the following equations correctly represents the reaction between magnesium and oxygen?
Answer
(C)
2Mg + O2 -> 2MgO
40
What is the formula for the sulfate ion?
Answer
(B)
SO4^2-
41
What is the charge on a sulfate ion?
Answer
(B)
2-
42
What is the formula for glucose?
Answer
(A)
C6H12O6
43
What type of reaction typically involves the movement of electrons?
Answer
(B)
Oxidation-reduction
44
What state is a substance that is a liquid in a chemical equation?
Answer
(B)
(l)
45
In the equation: 2H2 + O2 -> 2H2O, what is the number '2' in front of H2O called?
Answer
(B)
A coefficient
46
What is meant by the term 'balancing a chemical equation'?
Answer
(B)
Making sure the number of atoms of each element are equal on both sides.
47
What are the products when methane burns completely in air?
Answer
(D)
Carbon dioxide and water
48
What is the name of the compound with the formula Na2SO4?
Answer
(C)
Sodium sulfate
49
What is the name of the compound formed by the reaction between hydrogen and oxygen?
Answer
(C)
Water
50
What is the formula for the nitrate ion?
Answer
(A)
NO3-