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

MCQ

CH1 - STATES OF MATTER

Small crystals of purple $\text{KMnO}_4$ $(M_r = 158)$ and orange $\text{K}_2\text{Cr}_2\text{O}_7$ $(M_r = 294)$ were placed at the centres of separa...

2017 Summer

MCQ

CH2 - SEPARATING SUBSTANCES

Pure water has a boiling point of 100 °C and a freezing point of 0 °C. What is the boiling point and freezing point of a sample of aqueous sodium c...

2017 Summer

MCQ

CH2 - SEPARATING SUBSTANCES

A chromatogram obtained from the chromatography of four substances is shown. Which substance has an $R_f$ value of 0.6?

2017 Summer

MCQ

CH3 - ATOMS AND ELEMENTS

Sodium reacts with chlorine to form sodium chloride.Which statements describe what happens to the sodium atoms in this reaction?1. Sodium atoms form p...

2017 Summer

MCQ

CH3 - ATOMS AND ELEMENTS

Diamond is extremely hard and does not conduct electricity.Which statement explains these properties?

2017 Summer

MCQ

CH4 - ATOMS COMBINING

Which statement about metals is not correct?

2017 Summer

MCQ

CH4 - ATOMS COMBINING

Aluminium reacts with fluorine.$xAl(s) + yF_2(g) \rightarrow zAlF_3(s)$Which values of $x$, $y$ and $z$ balance the equation?[Table_1]

2017 Summer

MCQ

CH4 - ATOMS COMBINING

Carbon monoxide burns in oxygen to produce carbon dioxide. $$2\text{CO}(g) + \text{O}_2(g) \rightarrow 2\text{CO}_2(g)$$ Which mass of carbon dioxide...

2017 Summer

MCQ

CH1 - STATES OF MATTER

Which statement about electrolysis is correct?

2017 Summer

MCQ

CH1 - STATES OF MATTER

The reactivity series for a number of different metals is shown.[Image_1: Reactivity series and diagram]The diagram shows different metal strips dippe...

2017 Summer