BASIC CHEMISTRY Q&A QUIZ 4 – WINTER 2021

BASIC CHEMISTRY Q&A
QUIZ 4 – WINTER 2021
QUESTION 1
 Why is the first ionization energy of oxygen less than that of nitrogen?
The nitrogen atom has its outer electron in a different subshell
The nuclear charge on the oxygen atom is greater than that on the nitrogen atom
The oxygen atom has a pair of electrons in one p orbital that repel one another
There is more shielding in an oxygen atom
1 Mark

QUESTION 2
 Which statement about catalysts is correct?
They change the reaction pathway by increasing the activation energy
They increase the rate of reaction by lowering the enthalpy change of the reaction
They increase the number of particles that have sufficient energy to react
Heterogeneous catalysts are in the same state as the reactant
1 Mark

QUESTION 3
 Which substance will not be a product of the thermal decomposition of
hydrated magnesium nitrate?
Dinitrogen monoxide
Magnesium oxide
Oxygen
Steam
1 Mark

, QUESTION 4
 The volatility of the Group 17 elements, chlorine, bromine and iodine,
decreases down the group. What is responsible for this trend?
Bond length in the halogen molecule
Bond strength in the halogen molecule
Electronegativity of the halogen atom
Number of electrons in the halogen atom
1 Mark

QUESTION 5
 Chlorine gas is widely used to treat contaminated water. When chlorine is
added to water, which chemical species present is responsible for killing
bacteria?
ClO2–
Cl–
HCl
ClO–
1 Mark

QUESTION 6
 Which contains the largest number of hydrogen atoms?
0.10 mol of pentane
0.20 mol of but-2-ene
1.00 mol of hydrogen molecules
6.02 × 1023 hydrogen atoms
1 Mark