An environmental analyst is preparing a calibration standard of concentrated nitric acid (HNO3\text{HNO}_3HNO3) to analyze heavy metal contamination in a soil sample. Nitric acid is a strong, highly corrosive oxidizing agent that can release toxic nitrogen dioxide gas (NO2\text{NO}_2NO2) upon decomposition or reaction.
State one specific safety precaution, other than wearing a lab coat, that the analyst must take when preparing this calibration standard.
230 exam-style questions on Edexcel GCSE Chemistry 1.1 Formulae, equations and hazards, covering 1.1.1 Formulae, word and balanced equations, 1.1.2 Balanced ionic equations, and 1.1.3 Hazard symbols and risk in practical work. Each one has a worked solution and a mark scheme showing where the marks go.