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1.15 A piece of rock has a mass of 2.00 g. It contains calcium carbonate, but no other basic substances. It neutralises exactly 36.0 cm3 of 0.500 mol.dm–3 hydrochloric acid. What is the percentage of calcium carbonate in the 2.00 g piece of rock?

1.18 The equation for the complete combustion of propan-1-ol is shown.   Right-click on the button to open the data booklet in a new tab.        What is the standard enthalpy change of combustion of propan-1-ol, in kJ/mol?

1.29 Three elements, X, Y and Z, have electronic configurations as shown. X 2,6 Y 2,8,1 Z 2,8,7   Which formulae represent compounds that conduct electricity in the liquid state?   1 YZ 2 Y2X 3 Z2X

1.7 Methanol may be prepared by the reaction between carbon monoxide and hydrogen. CO(g) + 2H2(g) → CH3OH(g) The relevant average bond energies are given below. E (C ≡ O) 1077 kJ/ mol E (C – O) 360 kJ/ mol E (C – H) 410 kJ/ mol E (H – H) 436 kJ/ mol E (O – H) 460 kJ/ mol What is the enthalpy change of this reaction?

1.8 When nuclear reactions take place, the elements produced are different from the elements that reacted. Nuclear equations, such as the one below, are used to represent the changes that occur.     Right-click on the button to open the data booklet in a new tab.     The nucleon (mass) number total is constant at 236 and the proton number total is constant at 92. In another nuclear reaction, uranium-238 is reacted with deuterium atoms. An isotope of a new element, J, is formed as well as two neutrons.   Right-click on the button to open the data booklet in a new tab.   What is isotope J?     Right-click on the button to open the data booklet in a new tab.     

1.16 Which reaction does not contribute to the problem of acid rain?

1.12 Elements D and E are both in Period 3. Element D has the smallest atomic radius in Period 3. There are only two elements in Period 3 which have a lower melting point than element E. Elements D and E react together to form compound L. Which compound could be L  A  MgCl2 B MgS C Na2S D PCl 3

1.13 X and Y are both Group 2 metals. X and Y both form hydroxide compounds, but X(OH)2 is more soluble in water than Y(OH)2. If a piece of metal Y is put into cold water a very slow reaction occurs, and only few small hydrogen bubbles can be seen. What could the identities of X and Y be?  

1.11 Why is the ionic radius of a chloride ion larger than the ionic radius of a sodium ion?

1.26 How many of the following compounds produce a carboxylic acid on heating under reflux with an excess of hot acidified K2Cr2O7?   CH3CH2CHO CH3COCH3 CH3CH2CH2OH CH3CH(OH)CH3