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

Which diagram shows the process of diffusion?[Image_1: A, B, C, D diagrams with different atoms]

2012 Summer

Theory

CH2 - SEPARATING SUBSTANCES

Which method is most suitable to obtain zinc carbonate from a suspension of zinc carbonate in water?A) crystallisationB) distillationC) evaporationD) ...

2012 Summer

Theory

CH10 - THE SPEED OF A REACTION

A student investigates how the concentration of an acid affects the speed of reaction with a 0.5 g mass of magnesium at 30°C.The student has a beaker...

2012 Summer

Theory

CH3 - ATOMS AND ELEMENTS

An element Y has the proton number 18.The next element in the Periodic Table is an element Z.Which statement is correct?A. Element Z has one more elec...

2012 Summer

Theory

CH3 - ATOMS AND ELEMENTS

Which atom has twice as many neutrons as protons?A: $^1_1\text{H}$B: $^2_1\text{H}$C: $^3_1\text{H}$D: $^4_2\text{He}$

2012 Summer

Theory

CH4 - ATOMS COMBINING

Which is a simple covalent molecule?[Table_1]

2012 Summer

Theory

CH4 - ATOMS COMBINING

The electronic structures of atoms P and Q are shown.P and Q react to form an ionic compound.What is the formula of this compound?A. PQ2B. P2QC. P2Q6D...

2012 Summer

Theory

CH4 - ATOMS COMBINING

The diagrams show the structures of two forms, P and Q, of a solid element.What are suitable uses of P and Q, based on their structures?[Table_1]| |...

2012 Summer

Theory

CH5 - REACTING MASSES AND CHEMICAL EQUATIONS

The equation for the reaction between magnesium and dilute sulfuric acid is shown.$$\text{Mg } + \text{ H}_2\text{SO}_4 \rightarrow \text{MgSO}_4 + \t...

2012 Summer

Theory

CH1 - STATES OF MATTER

Winston Churchill, a British Prime Minister, had his false teeth electroplated with gold. The teeth were coated with a thin layer of carbon and were t...

2012 Summer