O-LevelChemistryBonding & Structure5070/22 · May/June 2023 · Q49 Marks
This question is about compounds that contain magnesium and nitrogen.
- (a)The formula for a nitride ion can be written as ¹⁵N³⁻. Complete Table 4.1 to show the number of particles in this nitride ion. [Table 4.1][3]
- (b)State why the formula for a magnesium ion is Mg²⁺ rather than Mg⁺ or Mg³⁺.[1]
- (c)The formula for a nitride ion is N³⁻. Deduce the formula for magnesium nitride.[1]
- (d)Magnesium nitrate, Mg(NO₃)₂, is an ionic compound. Predict two physical properties of magnesium nitrate. 1 2[2]
- (e)Calculate the percentage by mass of nitrogen in magnesium nitrate. Give your answer to two significant figures. percentage by mass[2]
Mark scheme
Marking points from the official mark scheme (May/June 2023). The mark or mark type is shown in brackets.
- 4(a) electron 10 (1)
- neutron 8 (1)
- proton 7 (1)
- 4(b) Mg2+ has full outer shell (of electrons) (1)
- 4(c) Mg3N2 (1)
- 4(d) soluble in water / dissolves in water(1)
- conducts electricity in (aqueous) solution (1)
- 4(e) Mr = 148 (1)
- % = 19% (1)
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →