Page 30 - Focus SPM KSSM F4 2020 - Chemistry

Chemistry Form 4 Chapter 3 The Mole Concept, Chemical Formula and Equation
5. Which of the following 8. What is the percentage C The number of atoms in
substances has the highest SPM composition by mass of the ammonia gas formed
number of atoms? HOTS 2018 carbon per molecule of is twice the number of
A 0.1 mole of carbon hexane, C H ? [Relative nitrogen atoms used
6
14
B 0.2 mole of zinc atomic mass: H,1; C, 12] D 1 mole of ammonia gas is
C 0.3 mole of chlorine gas A 76.23% C 83.72% formed when 0.5 mole of
D 0.4 mole of neon gas B 81.46% D 84.13% nitrogen gas reacts with
1.5 moles of hydrogen
9. 0.60 g of metal Z reacts with gas.
6. 200 cm of a gas has a mass
3
of 0.15 g at room conditions. fluorine to produce 1.17 g Z 12. The following equation
What is the molar mass of fluoride. What is the empirical SPM represents the reaction
the gas? formula of Z fluoride? 2018 between magnesium and
[Molar volume: 24 dm mol [Relative atomic mass: F,19; hydrochloric acid.
3
-1
Z, 40]
at room conditions] HOTS A ZF C Z F Mg(s) + 2HCl(aq) →
2
A 18 g mol -1 B ZF D ZF MgCl (aq) + H (g)
2
2
B 30 g mol -1 2 4 What is the volume of
C 50 g mol -1 10. What is the mass of calcium hydrogen produced if 3.6 g
D 150 g mol -1 contained in 1 kg of calcium of magnesium reacts with
Chapter
3 carbonate? excess hydrochloric acid at
3.3 Chemical Formula [Relative atomic mass: C,12; room conditions?
O, 16; Ca, 40] HOTS [Relative atomic mass: Mg,
24. Molar volume : 24 dm
3
7. The distinct smell of garlic A 100 g C 300 g mol at room conditions]
-1
SPM is due to the presence of B 200 g D 400 g A 0.12 dm 3
2018
allicin compound. Figure B 1.2 dm 3
3.23 shows the percentage C 3.6 dm 3
composition by mass of 3.4 Chemical Equation D 4.8 dm 3
allicin.
11. Ammonia gas is produced 13. Photosynthesis in green
SPM according to the following SPM plants can be represented by
2018 2017
equation: the following equation.
3H (g) + N (g) → 2NH (g) 6CO + 12H O sunlight
2 2 3 2 2
Which of the following C H O + 6O + 6H O
12
6
6
2
2
C, 44.4% H, 6.21% statements is true? What is the mass of glucose
O, 9.86% S, 39.5% A 3 g of hydrogen gas produced if 7.2 dm carbon
3
Figure 3.23 reacts with 1 g of dioxide gas is used?
What is the empirical formula nitrogen to produce 2 g of [Relative atomic mass : H,1;
C,12; O,16. Molar volume: 24
ammonia gas.
of allicin? dm mol at room conditions]
-1
3
A CHOS B Three molecules of A 18.00 g
B C H OS 2 nitrogen react with one B 9.00 g
molecule of hydrogen to
10
6
C C H OS 2 form two molecules of C 5.40 g
5
12
D C H OS 4 ammonia. D 4.91 g
12
10
Subjective Questions
Section A
1. The mass of an atom is very small. Therefore, chemists determine relative atomic mass of an element by
comparing the mass of the element with that of a standard atom. Figure 3.24 shows the comparison of the
mass of atom Y with carbon-12 atom.
Carbon-12
Y
C C C C
Figure 3.24
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03 SPM CHEMISTRY F4.indd 58 27/02/2020 11:23 AM