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 a cup of tea. Which row describes the water particles in the air above the cup compared with the water particles in the cup?[Table_1...

2013 Summer

Theory

CH11 - ACIDS AND BASES

Crystals of sodium chloride were prepared by the following method.1 25.0cm3 of dilute hydrochloric acid was accurately measured into a conical flask....

2013 Summer

Theory

CH11 - ACIDS AND BASES

Lead iodide is insoluble in water.Lead iodide is made by adding aqueous lead nitrate to aqueous potassium iodide.Which pieces of apparatus are needed ...

2013 Summer

Theory

CH3 - ATOMS AND ELEMENTS

Element X is represented by $^{27}_{13}X$.Which statement about element X is correct?A. An atom of X contains 13 protons and 13 neutrons.B. An atom of...

2013 Summer

Theory

CH12 - THE PERIODIC TABLE

The positions of four elements are shown on the outline of the Periodic Table.Which element forms a coloured oxide?

2013 Summer

Theory

CH4 - ATOMS COMBINING

For which substance is the type of bonding \textbf{not} correct?[Table_1]The table contains the following:\begin{center}\begin{tabular}{|c|c|c|c|}\hli...

2013 Summer

Theory

CH4 - ATOMS COMBINING

Element X has six electrons in its outer shell. How could the element react? A by gaining two electrons to form a positive ion B by losing six elec...

2013 Summer

Theory

CH1 - STATES OF MATTER

The diagram shows an incomplete circuit. Which substance causes the lamp to light when added to the glass tube? A. aqueous sodium chloride B. aqu...

2013 Summer

Theory

CH5 - REACTING MASSES AND CHEMICAL EQUATIONS

A compound with the formula XF$_2$ has a relative formula mass of 78.What is element X?A) argonB) calciumC) neonD) zirconium

2013 Summer

Theory

CH13 - THE BEHAVIOR OF METALS

What is the balanced chemical equation for the reaction between calcium and water?A. $\text{Ca} + \text{H}_2\text{O} \rightarrow \text{CaOH} + \text{H...

2013 Summer