1.7 g of \({\rm{NaN}}{{\rm{O}}_3}({M_r} = 85)\) is dissolved in water to prepare \({\text{0.20 d}}{{\text{m}}^{\text{3}}}\) of solution. What is the concentration of the resulting solution in \({\text{mol}}\,{\text{d}}{{\text{m}}^{ - 3}}\)?

A.     0.01

B.     0.1

C.     0.2

D.     1.0

B

Some respondents stated that the numbers could have been more user-friendly in these questions, as candidates do not have access to a calculator in P1. This is a fair comment which will be borne in mind for future paper-setting. Candidates found Q3 particularly challenging with only 35.79% of candidates getting the correct answer A. The inconsistent use of significant figures in Q2 was also commented on, equally a valid comment. One respondent stated that they found the use of \({\text{d}}{{\text{m}}^{\text{3}}}\) instead of L confusing for North American candidates. However on IB Chemistry papers the unit of \({\text{d}}{{\text{m}}^{\text{3}}}\) for volume is always used instead of L and candidates should be prepared for this.