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

The rate of diffusion of two gases, methane, CH₄, and ethene, C₂H₄, is measured using the apparatus shown.Which gas diffuses faster and why?

2016 Summer

MCQ

CH2 - SEPARATING SUBSTANCES

A sample of a dye is investigated by chromatography. A line is drawn across a piece of chromatography paper and a spot of the dye is placed on it.The ...

2016 Summer

MCQ

CH2 - SEPARATING SUBSTANCES

The paper chromatogram below was obtained from four different dyes.Which dye has an $R_f$ value of 0.7?

2016 Summer

MCQ

CH3 - ATOMS AND ELEMENTS

Which statements about isotopes of the same element are correct?1. They are atoms which have the same chemical properties because they have the same n...

2016 Summer

MCQ

CH4 - ATOMS COMBINING

The table shows the electronic structure of four atoms.[Table_1]atom | electronic structure---- | ------------------- W | 2,8,1 X | 2,8,4 Y | 2,...

2016 Summer

MCQ

CH4 - ATOMS COMBINING

Which statement describes the attractive forces between molecules (intermolecular forces)?

2016 Summer

MCQ

CH4 - ATOMS COMBINING

The diagram represents the general structure of a solid Z. What is Z?

2016 Summer

MCQ

CH6 - USING MOLES

A compound, X, contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass.The relative molecular mass, $M_r$, of X is 60.What is the molecular form...

2016 Summer

MCQ

CH11 - ACIDS AND BASES

25 cm$^3$ of 0.1 mol/dm$^3$ hydrochloric acid exactly neutralise 20 cm$^3$ of aqueous sodium hydroxide.The equation for this reaction is:NaOH + HCl $\...

2016 Summer

MCQ

CH1 - STATES OF MATTER

Which reactions could take place at the anode during electrolysis? 1. $4\text{OH}^-(aq) \rightarrow 2\text{H}_2\text{O}(l) + \text{O}_2(g) + 4e^-$ 2...

2016 Summer