IB Chemistry HL 1.2 The Nuclear Atom Question Bank

Practise IB Chemistry HL 1.2 with shared SL questions plus HL extensions in atomic structure, isotopes and mass spectra.

Covered syllabus points

2.1 The ionic model 2.2 The covalent model 2.3 The metallic model 2.4 From models to materials

[Maximum number: 1]

How does a lithium atom form the most stable ion?

The atom gains a proton to form a positive ion.

The atom loses a proton to form a negative ion.

The atom loses an electron to form a positive ion.

The atom gains an electron to form a negative ion.

[Maximum number: 4]

Phosphine (IUPAC name phosphane) is a hydride of phosphorus, with the formula $\mathrm{PH}_{3}$ .

(a)

Draw a Lewis (electron dot) structure of phosphine.

[ 1 ]

(b)

State the hybridization of the phosphorus atom in phosphine.

[ 1 ]

(c)

Outline whether you expect the bonds in phosphine to be polar or non-polar, giving a brief reason.

Figure for Question (c) — IB Chemistry HL

Phosphine has a much greater molar mass than ammonia. Explain why phosphine has a significantly lower boiling point than ammonia.

[ 2 ]

[Maximum number: 7]

Titanium and vanadium are consecutive elements in the first transition metal series.

(a)

Describe the bonding in metals.

[ 2 ]

(b)

Suggest why the melting point of vanadium is higher than that of titanium.

[ 1 ]

(c)

Explain why an aluminium-titanium alloy is harder than pure aluminium.

[ 2 ]

(d)

State the type of bonding in potassium chloride which melts at 1043 K .

[ 1 ]

(e)

A chloride of titanium, $\mathrm{TiCl}_{4}$ , melts at 248 K . Suggest why the melting point is so much lower than that of KCl .

[ 1 ]

«simple» molecular structure

OR

weak«er» intermolecular bonds

OR

weak«er» bonds between molecules

Marking guidance:

Accept specific examples of weak bonds such as London/dispersion and van der Waals.

Do not accept "covalent".

2.

h

i

$\mathrm{TiCl}_{4}(\mathrm{I})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{I}) \rightarrow \mathrm{TiO}_{2}(\mathrm{~s})+4 \mathrm{HCl}(\mathrm{aq})$

correct products

correct balancing

Accept ionic equation.

Award M2 if products are HCl and a compound of Ti and O.

2.

h

ii

HCl causes breathing/respiratory problems

OR

HCl is an irritant

OR

HCl is toxic

OR

HCl has acidic vapour

OR

HCl is corrosive

Accept $\mathrm{TiO}_{2}$ causes breathing problems/is an irritant.

Accept "harmful" for both HCl and $\mathrm{TiO}_{2}$ .

Accept "smoke is asphyxiant".

[Maximum number: 6]

Iron may be extracted from iron (II) sulfide, FeS.

(a)

Outline why metals, like iron, can conduct electricity.

[ 1 ]

(b)

Iron (II) sulfide, FeS, is ionically bonded.

[ 3 ]

(i)

Describe the bonding in this type of solid.

[ 2 ]

electrostatic attraction between oppositely charged ions/between $\mathrm{Fe}^{2+}$ and $\mathrm{S}^{2-}$

(ii)

Suggest why chemists find it convenient to classify bonding into ionic, covalent and metallic.

[ 1 ]

(c)

Explain why the addition of small amounts of carbon to iron makes the metal harder.

[ 2 ]

All question bank results loaded

Covered syllabus points

Structure 2. Models of bonding and structure question 1

Structure 2. Models of bonding and structure question 2

Question (a)

Question (b)

Question (c)

Structure 2. Models of bonding and structure question 3

Question (a)

Question (b)

Question (c)

Question (d)

Question (e)

Structure 2. Models of bonding and structure question 4

Question (a)

Question (b)

Question (i)

Question (ii)

Question (c)