Theory

CH7 - REDOX REACTIONS

The reactions shown may occur in the air during a thunder storm.$$ \text{N}_2 + \text{O}_2 \rightarrow 2\text{NO} $$$$ 2\text{NO} + \text{O}_2 \righta...

2009 Summer

Theory

CH7 - REDOX REACTIONS

The reactions shown may occur in the air during a thunder storm.$$N_2 + O_2 \rightarrow 2NO$$$$2NO + O_2 \rightarrow 2NO_2$$$$NO + O_3 \rightarrow NO_...

2009 Summer

Theory

CH7 - REDOX REACTIONS

The equations represent redox reactions.In which equation is the underlined substance acting as a reducing agent?A \underline{\text{CaO}} + \text{H}_2...

2009 Winter

Theory

CH7 - REDOX REACTIONS

The equations represent redox reactions. In which equation is the underlined substance acting as a reducing agent? \( A \) \( \underline{\text{CaO}}...

2009 Winter

Theory

CH7 - REDOX REACTIONS

The distinctive smell of the seaside was thought to be caused by ozone, $O_3$. Ozone is a form of the element oxygen.(a) A mixture of oxygen and ozone...

2009 Winter

Theory

CH7 - REDOX REACTIONS

The distinctive smell of the seaside was thought to be caused by ozone, $O_3$.Ozone is a form of the element oxygen.(a) A mixture of oxygen and ozone ...

2009 Winter

Theory

CH7 - REDOX REACTIONS

The following are examples of redox reactions.(a) Bromine water was added to aqueous sodium sulfide.$Br_2(aq) + S^{2-}(aq) \rightarrow 2Br^{-}(aq) + S...

2010 Summer

Theory

CH7 - REDOX REACTIONS

(a) Bromine water was added to aqueous sodium sulfide.$$\text{Br}_2(\text{aq}) + \text{S}^{2-}(\text{aq}) \rightarrow 2\text{Br}^-(\text{aq}) + \text{...

2010 Summer

Theory

CH7 - REDOX REACTIONS

The red colour in some pottery glazes may be formed as a result of the reactions shown.heat$\text{CuCO}_3 \rightarrow \text{CuO} + \text{CO}_2$$\text{...

2010 Winter

Theory

CH7 - REDOX REACTIONS

The red colour in some pottery glazes may be formed as a result of the reactions shown.$\text{CuCO}_3 \xrightarrow{\text{heat}} \text{CuO} + \text{CO}...

2010 Winter

Theory

CH1 - STATES OF MATTER

The diagram shows the result of dropping a purple crystal into water.Which processes take place in this experiment?[Table_1]| | chemical reac...

2014 Summer

Theory

CH2 - SEPARATING SUBSTANCES

The four pieces of apparatus shown below are used in chemical experiments.Which statement about the apparatus is correct?A. The burette measures the v...

2014 Summer

Theory

CH2 - SEPARATING SUBSTANCES

Alcohol and water are completely miscible. This means when mixed together they form only one liquid layer.Which method is used to separate alcohol fro...

2014 Summer

Theory

CH3 - ATOMS AND ELEMENTS

The diagram shows the structure of an atom of element X. What is X?A. boronB. carbonC. sodiumD. sulfur

2014 Summer

Theory

CH3 - ATOMS AND ELEMENTS

The diagrams show four particles. Which two diagrams show atoms that are isotopes of each other?A 1 and 2B 1 and 3C 2 and 3D 2 and 4

2014 Summer

Theory

CH4 - ATOMS COMBINING

The 'lead' in a pencil is made of a mixture of graphite and clay. When the percentage of graphite is increased, the pencil slides across the paper mor...

2014 Summer

Theory

CH4 - ATOMS COMBINING

Element X is in Group I of the Periodic Table. X reacts with element Y to form an ionic compound.Which equation shows the process that takes place whe...

2014 Summer

Theory

CH4 - ATOMS COMBINING

Solid F is an element.Solid G is a compound.Neither solid conducts electricity but G conducts electricity when dissolved in water.These properties sug...

2014 Summer

Theory

CH5 - REACTING MASSES AND CHEMICAL EQUATIONS

A compound contains one atom of calcium, two atoms of hydrogen and two atoms of oxygen.What is the correct chemical formula of the compound?A CaO_2H_2...

2014 Summer

Theory

CH5 - REACTING MASSES AND CHEMICAL EQUATIONS

In athletics, banned drugs such as nandrolone have been taken illegally to improve performance. Nandrolone has the molecular formula $C_{18}H_{26}O_{2...

2014 Summer