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Ionic bonding

Ionic bonding

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Question 5

Magnesium oxide, MgO\text{MgO}MgO, and potassium fluoride, KF\text{KF}KF, are ionic compounds.

a.

Calculate the relative formula mass (MrM_{\text{r}}Mr​) of MgO\text{MgO}MgO. (Take Ar: Mg=24A_{\text{r}}\text{: Mg} = 24Ar​: Mg=24, O=16\text{O} = 16O=16)

[1]
b.

Give the chemical formulae of the two ions present in KF\text{KF}KF.

[2]
c.

Explain why:

  • ionic compounds have high melting points
  • the melting point of magnesium oxide is much higher than the melting point of potassium fluoride
[4]
d.

Explain, in terms of structure and bonding, why ionic compounds do not conduct electricity when solid, but do conduct electricity when molten or in aqueous solution.

[3]
Markscheme

Ionic bonding Questions

  1. IGCSE
  2. /Chemistry
  3. /Ionic bonding

11 exam-style questions on Edexcel IGCSE Chemistry Ionic bonding. Each one has a worked solution and a mark scheme showing where the marks go.

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