CAIE
Chemistry
(9701)
Questions & Answers
Diamond and graphite are both crystalline solids made from carbon atoms. Graphite conducts electricity. Diamond does not conduct electricity. Name the type of lattice structure present in the crystalline solids diamond and graphite.
Explain how graphite conducts electricity.
Explain why diamond does not conduct electricity.
Separate samples of phosphorus(V) chloride and silicon(IV) chloride are each added to an excess of cold water. Write an equation for each reaction.
Describe the appearance of phosphorus(V) chloride and silicon(IV) chloride at room temperature.
Compare the appearance of the mixtures produced when each reaction is complete.
Some oxides are amphoteric. Describe what is meant by amphoteric.
Identify the formula of a Period 3 oxide that is amphoteric.
Complete Table 1.1 by identifying the strongest force of attraction in each oxide that is broken during melting. Use the abbreviations i.d. = instantaneous dipole-induced dipole, p.d. = permanent dipole-permanent dipole, H = hydrogen bond, C = covalent bond, I = ionic bond.
A student suggests the following hypothesis. The stronger the covalent bond between atoms in non-metal oxides, the higher the melting point. Use Table 1.1 to deduce if this hypothesis is true or false or if there is not enough information to make a conclusion. Explain your answer.
Define relative atomic mass.
Table 2.1 shows the abundances of two of the isotopes present in the sample of iron. Use Table 2.1 to calculate the relative isotopic mass of the third isotope of iron in the sample. Show your working.
Deduce the number of pairs of electrons in the 3d sub-shell in an iron(II) ion.
Sketch the shape of the lowest energy orbital in the shell with principal quantum number n = 2.
Complete Table 2.2 to show information about particles in one ion of 56Fe3+.
The atomic radius of iron is 1.26 × 10^-10 m. Suggest the change to the radius, if any, after an iron atom reacts to produce an Fe3+ ion. Explain your answer.
C3H6 reacts with HBr(g) in an addition reaction. Define addition reaction.
Complete Fig. 3.1 to show the mechanism for the addition reaction between C3H6 and HBr to produce 2-bromopropane. Include charges, dipoles, lone pairs of electrons and curly arrows, as appropriate.
Explain why the major product of this reaction is 2-bromopropane rather than 1-bromopropane.
H2(g) and nickel are added to alkene X. Fig. 3.2 shows how the concentration of X changes with time. Use Fig. 3.2 to identify the limiting reagent in this reaction. Explain your answer.
Use Fig. 3.2 to describe how the gradient changes as the reaction proceeds. State what this shows about the rate during this reaction.
Hydrocarbon Y contains two C=C groups. There are no other functional groups present. Y reacts with an excess of H2(g) to produce hexane, C6H14. Use Table 3.1 to calculate the enthalpy change per mole of C6H14 produced in this reaction.