Dinitrogen tetraoxide, N2O4(g), decomposes to nitrogen dioxide, NO2(g), in a sealed syringe of volume 2 dm3. The mixture reaches equilibrium at 325 °C according to the following balanced equation: When equilibrium is reached, it is observed that the colour of the gas in the syringe is brown. 6.1 State Le Chatelier’s principle. (2) 6.2 The … Read more
The reaction of zinc and EXCESS dilute hydrochloric acid is used to investigate factors that affect reaction rate. The balanced equation for the reaction is: The reaction conditions used and the results obtained for each experiment are summarised in the table below. The same mass of zinc is used in all the experiments. The zinc … Read more
4.1 Three reactions of organic compounds from the same homologous series are shown below. 4.1.1 Define a homologous series. (2) 4.1.2 Name the type of reaction represented by I. (1) 4.1.3 Write down the formula of the inorganic compound P. (1) 4.1.4 Give the structural formula of a POSITIONAL isomer of 2-bromobutane. … Read more
The boiling points of different organic compounds are given below. 3.1 Define boiling point. (2) 3.2 Write down the: 3.2.1 Name of the FUNCTIONAL GROUP of these compounds (1) 3.2.2 IUPAC name of compound C (1) 3.2.3 Structural formula of the FUNCTIONAL isomer of compound B (2) 3.3 Which ONE of … Read more
A test tube containing a straight chain organic acid X, ethanol and a catalyst is heated in a water bath as illustrated below. Organic compound Y is produced according to the following equation: 2.1 Give a reason why the test tube is heated in a water bath instead of directly over the flame. (1) … Read more
1.1 Which ONE of the following is the structural formula of the functional group of the KETONES? 1.2 Which ONE of the formulae below represents an ALKANE? A C2H4 B C5H10 C C14H30 D C8H14 (2) 1.3 Consider the organic compound below. The IUPAC name of this compound is … A 2,3-dimethyl … Read more
QUESTION 10 (Start on a new page.) The flow diagram below shows the processes involved in the industrial preparation ofan ammonium fertiliser. 10.1 Write down the NAME or FORMULA of: 10.1.1 Gas X (1) 10.1.2 Gas Y (1) 10.1.3 Acid Q (1) 10.2 Write down the: 10.2.1 TYPE of chemical reaction that converts compound P … Read more
QUESTION 9 (Start on a new page.) Chlorine is produced industrially by the electrolysis of a concentrated sodium chloridesolution, NaCℓ(aq). The balanced equation for the net (overall) cell reaction is as follows: 9.1 Define the term electrolysis. (2) 9.2 For the above reaction, write down the: 9.2.1 Half-reaction that takes place at the cathode (2) … Read more
QUESTION 8 (Start on a new page.) A standard electrochemical cell is set up using two standard half-cells, as shown in thediagram below. 8.1 State the energy conversion that takes place in this cell. (1) 8.2 What is the function of component Q? (1) X is a metal. A voltmeter connected across the cell initially … Read more
QUESTION 7 (Start on a new page.) A hydrogen bromide solution, HBr(aq), reacts with water according to the followingbalanced chemical equation: The Ka value of HBr(aq) at 25 °C is 1 x 109. 7.1 Is hydrogen bromide a STRONG ACID or a WEAK ACID? Give a reason for the answer. (2) 7.2 Write down the … Read more