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Essential Chemistry for IGCSE - Formulae And Equations (Section 1)

1
What is the name of the acid HCl?
Answer
(A)
Hydrochloric acid
2
What is the name of the compound with the formula MgCl2?
Answer
(A)
Magnesium chloride
3
What is the formula for the carbonate ion?
Answer
(B)
CO32-
4
Which of the following would increase the rate of a chemical reaction?
Answer
A
C
5
What is the name of the compound with the formula NH4Cl?
Answer
(B)
Ammonium chloride
6
Which type of reaction typically involves the transfer of electrons between atoms?
Answer
(C)
Redox
7
In the reaction: Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g). Which of the following are the products?
Answer
C
D
8
What is the meaning of (g) in a chemical equation?
Answer
(C)
Gas
9
Which of the following compounds is formed by a covalent bond?
Answer
(B)
H2O
10
What is the correct order of writing a chemical formula for an ionic compound?
Answer
(B)
Metal, then non-metal
11
In the reaction of zinc with hydrochloric acid, what type of reaction occurs?
Answer
(C)
Single displacement
12
What are the reactants in the reaction: 2H2 + O2 -> 2H2O?
Answer
(B)
H2 and O2
13
Which of the following is a characteristic of an acid?
Answer
(B)
Turns blue litmus paper red
14
What is the name given to the process where a solid is formed from a solution during a chemical reaction?
Answer
(C)
Precipitation
15
Which of the following is an example of a neutralization reaction?
Answer
(A)
A reaction between an acid and a base
16
What are the essential parts of a balanced chemical equation?
Answer
A
B
C
17
What type of reaction is represented in this equation: Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g)
Answer
(C)
Single displacement
18
Which of the following are examples of a compound?
Answer
A
C
19
In the reaction 2Na + 2H2O -> 2NaOH + H2, what does the 2 in front of NaOH represent?
Answer
(C)
The number of NaOH molecules
20
What is an aqueous solution?
Answer
(D)
A substance dissolved in water.
21
What is the formula for carbon monoxide?
Answer
(A)
CO
22
What is the valency of chlorine?
Answer
(A)
1
23
In an ionic compound, the metal is always written ____.
Answer
(A)
first
24
Which of the following is NOT a state symbol?
Answer
(D)
(w)
25
What is the process of balancing a chemical equation designed to achieve?
Answer
(B)
Equalizing the mass of reactants and products
26
What is a key characteristic of a balanced chemical equation?
Answer
(A)
The number of atoms of each element is the same on both sides of the equation.
27
Which elements are in the compound calcium hydroxide?
Answer
(A)
Calcium, Hydrogen, and Oxygen
28
Which type of formula shows the actual number of atoms in each element within a molecule?
Answer
(B)
Molecular formula
29
What is the formula for iron(III) oxide?
Answer
(B)
Fe2O3
30
In the formula for an ionic compound, how can you determine the number of each element needed?
Answer
(A)
By looking at the valency of each element
31
What does a catalyst do in a chemical reaction?
Answer
(A)
It speeds up the reaction.
32
What is the name of the compound with the formula K2O?
Answer
(A)
Potassium Oxide
33
Which of the following would cause a reaction to happen faster?
Answer
(C)
Adding a catalyst
34
Which two parts of a formula must be correct to write a chemical equation correctly?
Answer
A
D
35
What is the formula of the hydroxide ion?
Answer
(B)
OH-
36
What are the products when hydrogen reacts with oxygen?
Answer
(B)
Water
37
What does the symbol (s) in a chemical equation represent?
Answer
(B)
Solid
38
Which of these is a correct example of a molecular formula?
Answer
(B)
C2H4
39
Which of the following correctly represents the formula for Iron(II) chloride?
Answer
(B)
FeCl2
40
What is the name of the compound with the formula NaCl?
Answer
(A)
Sodium chloride
41
Which of the following is the correct representation of sulfuric acid?
Answer
(B)
H2SO4
42
In the balanced equation: 2H2 + O2 -> 2H2O, what does the '2' in front of H2O represent?
Answer
(C)
The number of water molecules
43
When writing the formula for a compound, how should you determine the order in which the elements are listed?
Answer
(C)
The metal is always first
44
What is the formula for potassium iodide?
Answer
(A)
KI
45
In a balanced equation, what do coefficients represent?
Answer
(A)
The number of molecules of each substance
46
Which of the following is/are true about a balanced chemical equation?
Answer
A
B
C
47
What is the chemical symbol for sodium hydroxide?
Answer
(B)
NaOH
48
Which of the following is a product of the reaction between sodium and chlorine?
Answer
(A)
Sodium chloride
49
What is the name of the compound with the chemical formula FeO?
Answer
(A)
Iron(II) oxide
50
What is the term for a chemical reaction where a solid product is formed?
Answer
(B)
Precipitation