IB Chemistry SL Structure 1: Particulate Nature of Matter

Explore how particulate models explain matter, from states and mixtures to atomic structure, electron configurations, the mole and ideal gases. Use experimental data, spectra and…

Covered syllabus points

1.1 Introduction to the particulate nature of matter 1.2 The nuclear atom 1.3 Electron configurations 1.4 The mole 1.5 Ideal gases

[Maximum number: 2]

Iron(II) sulfide can be produced by heating powdered iron and sulfur together.

Describe the difference between an element and a compound.

[Maximum number: 2]

Titanium is a transition metal.

(a)

State the number of protons, neutrons and electrons in the ${ }_{22}^{48} \mathrm{Ti}$ atom.

Protons:

Neutrons:

Electrons:

[ 1 ]

(b)

State the full electron configuration of the ${ }_{22}^{48} \mathrm{Ti}^{2+}$ ion.

[ 1 ]

$1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{6} 3 \mathrm{~s}^{2} 3 \mathrm{p}^{6} 3 \mathrm{~d}^{2}$

[Maximum number: 10]

Lithium and boron are elements in period 2 of the periodic table. Lithium occurs in group 1 (the alkali metals) and boron occurs in group 3. Isotopes exist for both elements.

(a)

Deduce the electron arrangements of the lithium ion, $\mathrm{Li}^{+}$ , and the boron atom, B .
$\mathrm{Li}^{+}$ :
B:

[ 2 ]

$\mathrm{Li}^{+}: 2 / 1 \mathrm{~s}^{2}$ ;
$B: 2,3 / 1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2} 2 \mathrm{p}^{1}$ ;

(b)

Naturally occurring boron exists as two isotopes with mass numbers of 10 and 11 . Calculate the percentage abundance of the lighter isotope, using this information and the relative atomic mass of boron in Table 5 of the Data Booklet.

[ 2 ]

correct mathematical expression set-up (e.g. $\left(\frac{x}{100}\right)(10)+\left[\frac{(100-x)}{(100)}\right](11)=10.81$ ); 19 \%;

Marking guidance:

Award [2] for correct final answer.

(c)

Every element has its own unique line emission spectrum.

[ 6 ]

(i)

Distinguish between a continuous spectrum and a line spectrum.

[ 2 ]

(ii)

Draw a diagram to show the electron transitions between energy levels in a hydrogen atom that are responsible for the two series of lines in the ultraviolet and visible regions of the spectrum. Label your diagram to show three transitions for each series.

[ 4 ]

[Maximum number: 1]

How many ions are present in 0.20 mol of $\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}$ ?

$0.20 \times 1 \times 6 \times 10^{23}$

$0.20 \times 2 \times 6 \times 10^{23}$

$0.20 \times 3 \times 6 \times 10^{23}$

$0.20 \times 7 \times 6 \times 10^{23}$

[Maximum number: 6]

Alkanes are commonly occurring organic compounds.

(a)

The first four straight chain alkanes are gases at room temperature.

Boiling points of straight chain alkanes

[ 6 ]

(i)

Explain why the volume occupied by a sample of propane increases sharply when the sample is heated up from 200 to 250 K at constant pressure.

[ 2 ]

(ii)

Calculate the volume, in $\mathrm{dm}^{3}$ , occupied by 6.45 g of propane gas at 100 kPa and $15^{\circ} \mathrm{C}$ .

[ 2 ]

$\begin{aligned} \text { « } \mathrm{Mr}\left(\mathrm{C}_{3} \mathrm{H}_{8}\right)=44.11 » \text { « } \mathrm{n}=\infty 0.146 \text { «mol» } \text { « } \mathrm{V}=\frac{0.146 \times 8.31 \times 288}{100} \Rightarrow 3.49 \text { «dm }{ }^{3} » \end{aligned}$

Award [2] for correct final answer.

Accept answers in the range 3.49-3.59 « $d m^{3}$ ».

(iii)

Outline why the volume occupied by propane(g) at very high pressure is higher than the value calculated using PV=nRT.

[ 2 ]

[Maximum number: 5]

Chlorine occurs in Group 7, the halogens.

(a)

Two stable isotopes of chlorine are ${ }^{35} \mathrm{Cl}$ and ${ }^{37} \mathrm{Cl}$ with mass numbers 35 and 37 respectively.

[ 5 ]

(i)

Define the term isotopes of an element.

[ 2 ]

(ii)

Using the mass numbers of the two isotopes and the relative atomic mass of chlorine from Table 5 of the Data Booklet, determine the percentage abundance of each isotope.

Percentage abundance ${ }^{35} \mathrm{Cl}$ :

Percentage abundance ${ }^{37} \mathrm{Cl}$ :

[ 2 ]

$\left(\right.$ for $\left.{ }^{35} \mathrm{Cl}: x \%\right) 35 x+3700-37 x=3545$ ;

Marking guidance:

Allow other alternative mathematical arrangements.
${ }^{35} \mathrm{Cl}=77.5 \%$ and ${ }^{37} \mathrm{Cl}=22.5 \%$ ;

Award [1 max] for correct percentages if no correct working is shown.

(iii)

Deduce the electron arrangement for the chloride ion, $\mathrm{Cl}^{-}$ .

[ 1 ]

2,8,8;

Marking guidance:

Allow $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6}$ or $[\mathrm{Ne}] 3 s^{2} 3 p^{6}$ or $[\mathrm{Ar}]$ .

All question bank results loaded

Covered syllabus points

Structure 1. Models of the particulate nature of matter question 1

Structure 1. Models of the particulate nature of matter question 2

Question (a)

Question (b)

Structure 1. Models of the particulate nature of matter question 3

Question (a)

Question (b)

Question (c)

Question (i)

Question (ii)

Structure 1. Models of the particulate nature of matter question 4

Structure 1. Models of the particulate nature of matter question 5

Question (a)

Question (i)

Question (ii)

Question (iii)

Structure 1. Models of the particulate nature of matter question 6

Question (a)

Question (i)

Question (ii)

Question (iii)