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 changes that occur when a substance changes state are shown below.Which process, W, X, Y or Z, is occurring in the following four situations?1. Bu...

2015 Summer

Theory

CH1 - STATES OF MATTER

A student uses the apparatus shown in the diagram below to measure the volume of carbon dioxide gas made when different masses of marble chips are add...

2015 Summer

Theory

CH3 - ATOMS AND ELEMENTS

Atoms contain electrons, neutrons and protons. What is the definition of nucleon number? A the number of neutrons in the nucleus of an atom B the numb...

2015 Summer

Theory

CH3 - ATOMS AND ELEMENTS

The diagram shows the atomic structure of an element X. What is X?A. aluminiumB. berylliumC. boronD. fluorine

2015 Summer

Theory

CH3 - ATOMS AND ELEMENTS

Which statements comparing the properties of electrons, neutrons and protons are correct?[Table_1]Table:| | neutrons and protons are both heavier th...

2015 Summer

Theory

CH4 - ATOMS COMBINING

Rescuers are drilling through fallen rock in order to rescue some men trapped in a cave. The drill needs lubricating from time to time.The following s...

2015 Summer

Theory

CH4 - ATOMS COMBINING

In which compounds are pairs of electrons shared between atoms?1. methane2. lead bromide3. sodium chlorideA. 1 onlyB. 2 onlyC. 1 and 3D. 1, 2 and 3

2015 Summer

Theory

CH5 - REACTING MASSES AND CHEMICAL EQUATIONS

What is the relative formula mass, $M_r$, of $CaCO_3$?A. 50B. 68C. 100D. 204

2015 Summer

Theory

CH1 - STATES OF MATTER

Copper and hydrogen can each be formed by electrolysis. At which electrodes are these elements formed? [Table_1]

2015 Summer

Theory

CH1 - STATES OF MATTER

The diagram shows a failed attempt to copper-plate a pan.Which action will plate the pan with copper?A. cooling the copper sulfate solution in an ice ...

2015 Summer