A student carries out a titration of 25.0 cm$^3$ of dilute nitric acid with 0.0450 mol/dm$^3$ barium hydroxide, using methyl orange as the indicator. Exactly 34.0 cm$^3$ of aqueous barium hydroxide neutralises the dilute nitric acid. Calculate the concentration of the dilute nitric acid.
Describe how to obtain pure dry crystals of barium nitrate from aqueous barium nitrate.
On heating, barium nitrate breaks down to make barium oxide, BaO, nitrogen dioxide, NO$_2$, and oxygen. Construct the equation for this reaction.
Nitrogen dioxide is an atmospheric pollutant that leads to ‘acid rain’. Describe one effect of acid rain on buildings.
Hydrazine, H$_2$N-NH$_2$, is a colourless liquid. Draw a dot-and-cross diagram for one molecule of hydrazine. Show only the outer-shell electrons.
The melting point of hydrazine is 2 ^{\circ}C. The boiling point of hydrazine is 114 ^{\circ}C. Use these facts to suggest why hydrazine is a solid at 0 ^{\circ}C.