Chemistry 9701/21 — May/June 2014

Cambridge AS Level · AS Level Structured Questions · worked solutions for every part, with the mark scheme

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Topics Atoms, Molecules and Stoichiometry · Chemical Bonding · Electrochemistry · Atomic Structure · Chemical Periodicity · Group 17 · +5 more

Q1Atomic StructureAtoms, Molecules and StoichiometryChemical PeriodicityChemical BondingFree sample

(a)

Explain what is meant by the term ionisation energy.

(b)

The first seven ionisation energies of an element, A, in $\text{kJ mol}^{-1}$ , are

1012 \quad 1903 \quad 2912 \quad 4957 \quad 6274 \quad 21269 \quad 25398

(i)

State the group of the Periodic Table to which A is most likely to belong. Explain your answer.

(ii)

Complete the electronic configuration of the element in Period 2 that is in the same group as A.

$1\text{s}^2$ .................................................................................................................................

(c)

Another element, Z, in the same period of the Periodic Table as A, reacts with chlorine to form a compound with empirical formula $\mathbf{Z}\text{Cl}_2$ . The percentage composition by mass of $\mathbf{Z}\text{Cl}_2$ is Z, 31.13; $\text{Cl}$ , 68.87.

(i)

Define the term relative atomic mass.

(ii)

Calculate the relative atomic mass, $A_r$ , of Z.
Give your answer to three significant figures.

(d)

The chlorides of elements in Period 3 of the Periodic Table show different behaviours on addition to water, depending on their structure and bonding.

(i)

Write equations to show the behaviour of sodium chloride, $\text{NaCl}$ , and silicon chloride, $\text{SiCl}_4$ , when separately added to an excess of water.

$\text{NaCl}$ ...................................................................................................................................

$\text{SiCl}_4$ ...................................................................................................................................

(ii)

State and explain the differences in behaviour of these two chlorides when added to water, in terms of their structure and the bonding found in the compounds.

(e)

Sulfur reacts with fluorine to form $\text{SF}_6$ . State the shape and bond angle of $\text{SF}_6$ .

shape of $\text{SF}_6$ ..............................................................................................................................

bond angle of $\text{SF}_6$ ......................................................................................................................

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3 more questions

Q2Electrochemistry · Atoms, Molecules and Stoichiometry9M
Q3Group 17 · Chemical Bonding · Electrochemistry13M
Q4Hydrocarbons · Introduction to Organic Chemistry · Polymerisation · Halogen Compounds · Nitrogen Compounds20M

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