Online quiz 2

1.

1 point

Self-igniting flares contain Mg3P2. With water this produces diphosphane, P2H4, which is spontaneously flammable in air.
Which equation that includes the formation of diphosphane is balanced?

A Mg3P2 + 6H2O -> 3Mg(OH)2 + P2H4

B Mg3P2 + 6H2O -> 3Mg(OH)2 + P2H4 + H2

C 2Mg3P2 + 12H2O -> 6Mg(OH)2 + P2H4 + 2PH3

D 2Mg3P2 + 12H2O -> 6Mg(OH)2 + 3P2H4

2.

1 point

What is the order of increasing energy of the listed orbitals in the atom of titanium?

A 3s 3p 3d 4s

B 3s 3p 4s 3d

C 3s 4s 3p 3d

D 4s 3s 3p 3d

3.

1 point

John Dalton’s atomic theory, published in 1808, contained four predictions about atoms.
Which of his predictions is still considered to be correct?

A Atoms are very small in size.

B No atom can be split into simpler parts.

C All the atoms of a particular element have the same mass.

D All the atoms of one element are different in mass from all the atoms of other elements D All the atoms of one element are different in mass from all the atoms of other elements D All the atoms of one element are different in mass from all the atoms of other elements D All the atoms of one element are different in mass from all the atoms of other elements D All the atoms of one element are different in mass from all the atoms of other elements D All the atoms of one element are different in mass from all the atoms of other elements D. All the atoms of one element are different in mass from all the atoms of other elements

4.

1 point

Use of the Data Booklet is relevant to this question.
In leaded petrol there is an additive composed of lead, carbon and hydrogen only.
This
compound contains 29.7 % carbon and 6.19 % hydrogen by mass.
What is the value of x in the empirical formula PbC8HX?

A 5

B 6

C 16

D 20

5.

1 point

Gallium nitride, GaN, could revolutionise the design of electric light bulbs because only a small length used as a filament gives excellent light at low cost.
Gallium nitride is an ionic compound containing the Ga3+ ion.

What is the electron arrangement of the nitrogen ion in gallium nitride?

A 1s2 2s2

B 1s2 2s2 2p3

C 1s2 2s2 2p4

D 1s2 2s2 2p6

6.

1 point

A sample of chlorine containing isotopes of mass numbers 35 and 37 was analysed in a
mass-spectrometer. How many peaks corresponding to Cl 2 + were recorded?

A 2

B 3

C 4

D 5

7.

1 point

N2O4 is a poisonous gas. It can be disposed of safely by reaction with sodium hydroxide.

N2O4(g) + 2NaOH(aq) → NaNO3(aq) + NaNO2(aq) + H2O(l)

What is the minimum volume of 0.5 mol dm–3 NaOH(aq) needed to dispose of 0.02 mol of N2O4?

A 8 cm3

B 12.5 cm3

C 40 cm3

D 80 cm3

8.

1 point

Use of the Data Booklet is relevant to this question.
What could be the proton number of an element that has three unpaired electrons in each of its atoms?

A 5

B 13

C 15

D 21

9.

1 point

Use of the Data Booklet is relevant to this question.
Nickel makes up 20 % of the total mass of a coin. The coin has a mass of 10.0 g.
How many nickel atoms are in the coin?

A 2.05 × 1022

B 4.30 × 1022

C 1.03 × 1023

D 1.20 × 1024

10.

1 point

A household bleach contains sodium chlorate(I), NaClO, as its active ingredient. The concentration of NaClO in the bleach can be determined by reacting a known amount with aqueous hydrogen peroxide, H2O2.
NaClO(aq) + H2O2(aq) → NaCl(aq) + O2(g) + H2O(l)
When 25.0 cm3 of bleach is treated with an excess of aqueous H2O2, 0.0350 mol of oxygen gas is given off.
What is the concentration of NaClO in the bleach?

A 8.75 × 10–4 mol dm–3

B 0.700 mol dm–3

C 0.875 mol dm–3

D 1.40 mol dm–3

11.

1 point

Use of the Data Booklet is relevant to this question.
A typical solid fertiliser for use with household plants and shrubs contains the elements N, P, and K in the ratio of 15 g : 30 g :15 g per 100 g of fertiliser. The recommended usage of fertiliser is 14 g of fertiliser per 5 dm3 of water.
What is the concentration of nitrogen atoms in this solution?

A 0.03 mol dm–3

B 0.05 mol dm–3

C 0.42 mol dm–3

D 0.75 mol dm–3

12.

1 point

On collision, airbags in cars inflate rapidly due to the production of nitrogen.
The nitrogen is formed according to the following equations.
2NaN3 → 2Na + 3N2
10Na + 2KNO3 → K2O + 5Na2O + N2
How many moles of nitrogen gas are produced from 1 mol of sodium azide, NaN3?

A 1.5

B 1.6

C 3.2

D 4.0

13.

1 point

Helium, He, is the second element in the Periodic Table.
Tritium is the isotope of hydrogen 3H.
What is the same in an atom of 4He and an atom of 3H?

A the number of electrons

B the number of neutrons

C the number of protons

D the relative atomic mass

14.

1 point

In the Basic Oxygen steel-making process the P4O10 impurity is removed by reacting it with calcium oxide. The only product of this reaction is the salt calcium phosphate, Ca3(PO4)2.

In this reaction, how many moles of calcium oxide react with one mole of P4O10?

A 1

B 1.5

C 3

D 6

15.

1 point

A simple ion X + contains eight protons.
What is the electronic configuration of X+?

A 1s2 2s1 2p6

B 1s2 2s2 2p3

C 1s2 2s2 2p5

D 1s2 2s2 2p7

16.

1 point

Use of the Data Booklet is relevant to this question.
Oxides of nitrogen are pollutant gases which are emitted from car exhausts.
In urban traffic, when a car travels one kilometre, it releases 0.23 g of an oxide of nitrogen NxOy, which occupies 120 cm3.
What are the values of x and y?
(Assume 1 mol of gas molecules occupies 24.0 dm3.)

A x = 1, y = 1

B x = 1, y = 2

C x = 2, y = 1

D x = 2, y = 4

17.

1 point

A radioactive isotope of thallium, 201 81 Tl, is used to assess damage in heart muscles after a heart attack. (201 is mass number, 81 is atomic number in this order).
Which statement about 201 81 Tl is correct?

A This isotope has a nucleon number of 120

B The number of electrons in one atom of this isotope is 81.

C The number of neutrons in one atom of this isotope is 201.

D X 201 82 is an isotope of 201 81 Tl

18.

1 point

Which of these samples of gas contains the same number of atoms as 1g of hydrogen (Mr : H2, 2)?

A 22 g of carbon dioxide (Mr : CO2, 44)

B 8 g of methane (Mr : CH4, 16)

C 20 g of neon (Mr : Ne, 20)

D 8 g of ozone (Mr : O3, 48)