Topic 6 Nitrogen and Its Compounds

Ammonia is a Lewis base because

• it can turn litmus paper to blue

• it reacts with acid to produce salt and water

• it has lone donor pair electrons

• it can produce OH^- ions in water

Which of the following statements is not correct based on the reaction equation below?

3H_2(g) + 2N_2(g) --> 2NH_3(g)

• It is an exothermic reaction

• The yield of ammonia will increase with an increase in temperature

• Finely divided iron is used as catalyst

• This process is used to manufacture ammonia in big scale

Nitrogen is inert because

• it has one lone pair electrons

• it is in the gas state

• it has high enthalpy of atomization

• it is a non polar molecule

Which of the following is not true regarding ammonia?

• It has a pyramidal shape.

• Ammonia is a lewis base.

• It dissolved in water to form ammonium solution.

• Aqueous ammonia will reduce copper(II) to copper.

Nitrates are poisonous to human if consumed because

• It oxidize the iron(II) in haemoglobin to iron (III)

• it react with water in the body to form nitric acid.

• It decomposes the poisonous nitrogen dioxide

• It is oxidized to uric acid in the body

Which of the following is not correct regarding nitrogen monoxide, NO?

• It acts as a free radical

• It is highly reactive

• It is a colourless gas

• It is a V-shape molecule

The following are correct about Ostwald process except for

• Temperature of 850 ^oC is used for the first stage of the process

• Using finely divided iron as catalyst

• The temperature need to be lowered for the second stage

• Excess oxygen for the overall process

Which of the following is a correct observation for the reaction of Mg²⁺ with ammonia solution?

• Forms blue precipitate

• Soluble in excess ammonia

• Turn to light brown on standing

• Forms white precipitate

Which of the following is incorrect about Stage 3 of Ostwald process?

• Nitric acid that formed is in aqueous state

• In the presence of oxygen and water, NO gas that formed will be recycle

• In the absence of oxygen, nitric acid that formed will be concentrated by distillation

• It occurs in absorption tower

Choose incorrect statement about nitrogen oxides?

• N₂O₄ is a colourless liquid at temperature below 21 ^oC.

• NO₂ is a brown gas that will decompose above 140 ^oC.

• NO is a toxic, colourless gas which is a primary air pollutant.

• Colourless gas of N₂O₄ is a acidic gas.