Cambridge IGCSE Chemistry - 0620 - Core Paper 1 2010 Winter Zone 2

In which changes do the particles move further apart?

A mixture of ethanol and methanol are separated by fractional distillation. This method of separation depends on a difference in property X of these two alcohols. What is property X?

Chromatography is used to find out if a banned dye, P, is present in foodstuffs. The results are shown in the diagram.
Which foodstuff contains P?

Which diagram does not show the outer shell electrons in the molecule correctly?

The chemical compositions of two substances, W and X, are given.
W \( \text{Na(AlSi}_3\text{)O}_8 \)
X \( \text{Ca(Al}_2\text{Si}_2\text{)O}_8 \)
Which statements are correct?
1. W and X contain the same amount of oxygen.
2. W contains three times as much silicon as X.
3. X contains twice as much aluminium as W.

The electronic structures of atoms X and Y are shown.

X and Y form a covalent compound.
What is its formula?

Element X is shiny and can be formed into a sheet by hammering. Which row correctly describes the properties of element X? [Table_1]

Two isotopes of hydrogen are $^1H$ and $^2H$.
Which diagram shows the arrangement of particles in the two isotopes?

The table shows the structure of different atoms and ions.
[Table_1]
What are the values of W, X, Y and Z?
[Table_2]

Element X has a nucleon (mass) number of 19 and a proton (atomic) number of 9. To which group in the Periodic Table does it belong?

Substance X was electrolysed in an electrolytic cell.
A coloured gas was formed at the anode and a metal was formed at the cathode.

What is substance X?

The diagram shows apparatus used in an attempt to electroplate a metal ring with copper.

The experiment did not work.
What change is needed in the experiment to make it work?

When concentrated sodium chloride solution is electrolysed, elements X and Y are formed.

What are X and Y?

Calcium carbonate was reacted with hydrochloric acid in a conical flask. The flask was placed on a balance and the mass of the flask and contents was recorded as the reaction proceeded.
During the reaction, carbon dioxide gas was given off.
The reaction was carried out at two different temperatures.
Which row is correct?
[Table_1]

Some barium iodide is dissolved in water. Aqueous lead(II) nitrate is added to the solution until no more precipitate forms. This precipitate, X, is filtered off. Dilute sulfuric acid is added to the filtrate and another precipitate, Y, forms. What are the colours of precipitates X and Y?

When pink crystals of cobalt(II) chloride are heated, steam is given off and the colour of the solid changes to blue.

$\text{CoCl}_2\cdot6\text{H}_2\text{O} \leftrightarrow \text{CoCl}_2 + 6\text{H}_2\text{O}$

What happens when water is added to the blue solid?
[Table_1]

The diagrams show some pieces of laboratory equipment:

Which equipment is needed to find out whether dissolving salt in water is an endothermic process?

Which reaction will result in a decrease in pH?

Which is an endothermic process?

The red colour in some pottery glazes may be formed as a result of the reactions shown.

$\text{heat}$
CuCO$_3$ $\rightarrow$ CuO + CO$_2$
CuO + SnO $\rightarrow$ Cu + SnO$_2$

These equations show that ......1...... is oxidised and ......2...... is reduced.

Which substances correctly complete gaps 1 and 2 in the above sentence?

The table shows some reactions of the halogens.
Which reaction is the most likely to be explosive?
[Table showing reactions of chlorine gas, bromine gas, and iodine gas]

Which compound is likely to be coloured?

A salt is made by adding an excess of an insoluble metal oxide to an acid. How can the excess metal oxide be removed?

The oxide of element X was added to an acid. It reacted to form a salt and water.
What is the pH of the acid before the reaction and what type of element is X?

The table compares the properties of Group I elements with those of transition elements. Which entry in the table is correct? [Table_1]

The diagram shows the positions of elements P, Q, R, S and T in the Periodic Table. These letters are not the chemical symbols for the elements.



Which statement about the properties of these elements is correct?

Some metals react readily with dilute hydrochloric acid.
Some metals can be extracted by heating their oxides with carbon.
For which metal are both statements correct?

Which diagram could represent the structure of an alloy?

The diagram shows the materials used in the production of steel from impure iron.

What could element X be?

Which property do all metals have?

Which pollutant, found in car exhaust fumes, does not come from the fuel?

Which diagram shows a common use of stainless steel?

Why is chlorination used in water treatment?

A test-tube containing damp iron wool is inverted in water. After three days, the water level inside the test-tube has risen.
Which statement explains this rise?

Which information about carbon dioxide and methane is correct?
[Table_1]

A bag of fertiliser 'Watch it grow' contains ammonium sulfate and potassium sulfate.
Which of the three elements N, P and K does 'Watch it grow' contain?
[Table_1]

In an oil refinery, crude oil is separated into useful fractions. The diagram shows some of these fractions.

What are fractions X, Y and Z?

Ethene reacts with Y to produce ethanol.
ethene + Y \rightarrow ethanol
What is Y?

The diagram shows the structure of a compound.

To which classes of compound does this molecule belong?
[Table_1]

Which structures show compounds that are members of the same homologous series?