Introduction to the Particulate Nature of Matter (DP IB Chemistry: SL)

A sample of pure solid sulfur dioxide was slowly heated from –100 °C, which is below its melting point, to 0 °C, which is above its boiling point. Its temperature is measured every minute and the results are represented on the graph.

i) Complete the equation for the equilibrium present in the region BC.

SO₂ (s) ....................

[1]

ii) What is the physical state of SO₂ in the region after E?

[1]

iii) What would be the difference in the region BC if an impure sample of SO₂ had been used?

[1]

Using the graph in part (a), complete the table by comparing the separation and movement of the molecules in regions A to B with those in C to D

Explain why the temperature remains constant between B and C.

Solid iodine has the structure shown below.

Under standard conditions (298.15 K and 100 kPa) it will undergo sublimation

i) Write a symbol equation for the deposition of gaseous iodine and explain why this is described as a physical process

[2]

ii) State and explain whether this change is exothermic or endothermic

[1]

Explain why gaseous iodine occupies a significantly greater volume than solid iodine.

State two physical differences between solid iodine and gaseous iodine.

During the manufacture of a commercial drink, a batch containing water, sugar, dyes and flavouring concentrates became contaminated with an unknown solid during the mixing process.

i) State the type of mixture that best describes this batch.

[1]

ii) Draw a labelled set of apparatus required to isolate the solid particles in the mixture

[2]

i) State the method that could be used to isolate the dissolved solids, such as dyes and flavourings, from the mixture.

[1]

ii) State the method that could be used to separate the dyes and flavourings once they have been isolated.

[1]

Once the flavourings have been separated chromatography is used to identify them. The sample was labelled X.

A, B and C are reference flavourings used in this process.

i) Identify which flavourings are present in sample X.

[1]

ii) Identify, giving a reason, the least soluble flavouring.

[1]

Describe how an increase in temperature affects the movement of particles in a liquid.

Carbon is an element in Group 14.

C₆₀ sublimes at approximately 800 K.

C₆₀ (s) → C₆₀ (g)

Diamond also sublimes but only above 3800 K.

C_diamond (s) → C (g)

Explain, with reference to their structure and properties, why C₆₀ and diamond sublime at such different temperatures.

0.144 g of C₆₀ is placed in a 100 x 10^-6 m³ container of hydrogen gas at a temperature of 25 °C and a pressure of 100 kPa.

The container is heated to make the C₆₀ and hydrogen gas react. The reaction occurs as shown in the equation.

C₆₀ (s) + xH₂ (g) → C₆₀H_2x (s)

After the reaction, the container is allowed to cool to 25 °C. The pressure decreases to 20.8 kPa. All of the C₆₀ has reacted. 

i) Calculate the amount, in mols, of C₆₀ that reacts.

[1]

ii) Calculate the amount, in mols, of hydrogen gas that reacted with the C₆₀.

[3]

iii) Use your answers from (ii) and (iii) to deduce the correct balanced equation.

[3]

An ink is a mixture of coloured substances dissolved in water.

A sample of ink, K, is known to contain three different coloured substances.

Discuss the use of the following methods to separate the coloured substances in the sample of ink, K.

• chromatography

• crystalisation

• filtration

• fractional distillation

• simple distillation

Chromatography can be used to separate a mixture of ions from different transition element compounds.

Two solutions, Y and Z were placed on a piece of chromatography paper.

Four samples, R, S, T and U, each containing transition element ions, were also placed on the same piece of chromatography paper.

The results of the chromatography are shown.

i) Explain the results shown for solutions Y and Z. 

[1]

 ii) Which sample does not contain the same ions as either solution Y or solution Z? 

[1] 

iii) Which sample contains the same ions as both solution Y and solution Z? 

[1] 

iv) Which sample has the greatest number of transition element ions?

[1] 

12.2 g of hydrated iron(II) sulfate, FeSO₄.xH₂O were dissolved in acidic solution and made up to a volume of 500 cm³.  A 25.0 cm³ sample of this solution was titrated against 0.0200 mol dm^-3 potassium manganate(VII) solution.  21.95 cm³ of this solution were required.

The following reaction took place:

5Fe²⁺+ MnO₄^- + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂O

i) Calculate the amount, in mol, of MnO₄^-

[1]

ii) Calculate the amount, in mol, of Fe²⁺ in the original sample

[2]

iii) Calculate the value of x in FeSO₄.xH₂O

[2]

Krypton is a gas at room temperature. Krypton atoms, are spread far apart and move in a random manner at high speed. Krypton is shipped as a liquid.

Compare the movement and arrangement of the molecules in liquid krypton to those in krypton gas.

A sealed container contains krypton gas. 

Explain why the pressure inside the container increases when the temperature is increased.

Explain why gases expand to fill their containers.