Problem 45
Write balanced equations for the preparation of sodium nitrite by (a) heating sodium nitrate and (b) heating sodium nitrate with carbon.
Problem 46
Sodium amide \(\left(\mathrm{NaNH}_{2}\right)\) reacts with water to produce sodium hydroxide and ammonia. Describe this reaction as a Brønsted acid-base reaction.
Problem 47
Write a balanced equation for the formation of urea, \(\left[\left(\mathrm{NH}_{2}\right)_{2} \mathrm{CO}\right],\) from carbon dioxide and ammonia. Should the reaction be run at a high or low pressure to maximize the yield?
Problem 48
Some farmers feel that lightning helps produce a better crop. What is the scientific basis for this belief?
Problem 49
Explain why nitric acid can be reduced but not oxidized.
Problem 50
At \(620 \mathrm{~K}\), the vapor density of ammonium chloride relative to hydrogen \(\left(\mathrm{H}_{2}\right)\) under the same conditions of temperature and pressure is \(14.5,\) although, according to its formula mass, it should have a vapor density of 26.8 . How would you account for this discrepancy?
Problem 51
Write a balanced equation for each of the following processes: (a) On heating, ammonium nitrate produces nitrous oxide. (b) On heating, potassium nitrate produces potassium nitrite and oxygen gas. (c) On heating, lead nitrate produces lead(II) oxide, nitrogen dioxide \(\left(\mathrm{NO}_{2}\right),\) and oxygen gas.
Problem 52
Explain why, under normal conditions, the reaction of zinc with nitric acid does not produce hydrogen.
Problem 53
Explain why two \(\mathrm{N}\) atoms can form a double bond or a triple bond, whereas two \(\mathrm{P}\) atoms normally can form only a single bond.
Problem 54
Starting with elemental phosphorus \(\left(\mathrm{P}_{4}\right)\), show how you would prepare phosphoric acid.
