Theory

CH18 - POLYMERS

Lactic acid can be made from corn starch. It polymerises to form the polymer, polylactic acid (PLA) which is biodegradable. (a) Suggest two advant...

2009 Summer

Theory

CH18 - POLYMERS

A macromolecule is a very large molecule. Macromolecules can be made by joining smaller molecules together. This is called polymerisation. Which row i...

2010 Summer

Theory

CH18 - POLYMERS

A macromolecule is a very large molecule.Macromolecules can be made by joining smaller molecules together. This is called polymerisation.Which row in ...

2010 Summer

Theory

CH18 - POLYMERS

A macromolecule is a very large molecule.Macromolecules can be made by joining smaller molecules together. This is called polymerisation.Which row in ...

2010 Summer

Theory

CH18 - POLYMERS

Hydrolysis is used in chemistry to break down complex molecules into simpler ones.(a) Compounds containing the group $\overset{O}{\parallel}C$ or $\te...

2010 Summer

Theory

CH18 - POLYMERS

The hydrolysis of complex carbohydrates to simple sugars is catalysed by enzymes called carbohydrases and also by dilute acids.(a) (i) They are both c...

2010 Summer

Theory

CH18 - POLYMERS

The hydrolysis of complex carbohydrates to simple sugars is catalysed by enzymes called carbohydrases and also by dilute acids.(a) (i) They are both c...

2010 Summer

Theory

CH18 - POLYMERS

Monomers polymerise to form polymers or macromolecules.(a) (i) Explain the term polymerise...............................................................

2010 Winter

Theory

CH18 - POLYMERS

In the absence of oxygen, certain bacteria decompose carbohydrates to biogas. This is a mixture of gases mainly methane and carbon dioxide. Biogas is ...

2010 Winter

Theory

CH18 - POLYMERS

Synthetic polymers are widely used in the modern world.(a) Their use has brought considerable advantages to modern life as well as some disadvantages....

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