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

CH15 - AIR AND WATER

This question is about the first 30 elements in the Periodic Table. Name the element which: (a) is 78% of clean, dry air ................................

2022 Spring

Theory

CH4 - ATOMS COMBINING

(a) Add the missing state symbols to the chemical equation for the reaction.MgCO$_3$ ..... + 2HCl ..... $\rightarrow$ MgCl$_2$(aq) + H$_2$O ..... + CO...

2022 Spring

Theory

CH15 - AIR AND WATER

Nitrogen dioxide, NO$_2$, is an atmospheric pollutant and is formed in car engines.(a) Explain how nitrogen dioxide is formed in car engines.............

2022 Spring

Theory

CH13 - THE BEHAVIOR OF METALS

This question is about chemical reactions and electricity.(a) The diagram shows the apparatus used in the production of electrical energy in a simple ...

2022 Spring

Theory

CH17 - ORGANIC CHEMISTRY

This question is about alkanes and alkenes.(a) Short-chain alkanes and alkenes can be formed from long-chain alkanes in a chemical reaction.(i) Name t...

2022 Spring

Theory

Plastics

The names of four esters are listed. methyl propanoate ethyl propanoate propyl propanoate butyl propanoate (a) Esters are a family of organic...

2022 Spring

MCQ

CH1 - STATES OF MATTER

Which two gases will diffuse at the same rate, at the same temperature?

2022 Summer

MCQ

CH1 - STATES OF MATTER

A student measures the time taken for 2.0 g of magnesium to dissolve in 50 cm\(^3\) of dilute sulfuric acid. Which apparatus is essential to complete ...

2022 Summer

MCQ

CH3 - ATOMS AND ELEMENTS

The numbers of protons and neutrons and the electronic structures of four particles, W, X, Y and Z, are shown.[Table_1]Which particles have the same c...

2022 Summer

MCQ

CH3 - ATOMS AND ELEMENTS

Which substance should be pure for the intended use?

2022 Summer