CI.1

Question 1

Why is nitrogen so unreactive?

Answer 1

Nitrogen molecules contain two nitrogen atoms bonded together by a triple bond, which is very strong and requires a lot of energy to overcome.

Question 2

What conditions are often required for molecular nitrogen to react?

Answer 2

High temperature and pressure, as well as a catalyst.

Question 3

What is the equation for the haber process to make ammonia from nitrogen and hydrogen?

Answer 3

N2(g) + 3H2(g) ⇌ 2NH3(g)

Question 4

What does ammonia have to be able to form a dative covalent bond to hydrogen ions to give ammonium ions?

Answer 4

A lone pair of electrons.

Question 5

What are the three main nitrogen oxides?

Answer 5

• NO, nitrogen monoxide.
• NO2, nitrogen dioxide.
• N2O, dinitrogen monoxide

Question 6

What is the appearance of nitrogen monoxide?

Answer 6

Colorless gas.

Question 7

What is the appearance of nitrogen dioxide?

Answer 7

Brown gas.

Question 8

What is the appearance of dinitrogen monoxide?

Answer 8

Colorless gas.

Question 9

Why does NO turn rapidly into NO2 in the atmosphere?

Answer 9

It is very reactive as it is a radical, although NO2 is still a radical it is more stable.

Question 10

What are the main ways NO are produced?

Answer 10

Combustion processes in vehicle as well as thunderstorms.

Question 11

Out of NO, NO2, and N2O, which are toxic gases?

Answer 11

NO and NO2.

Question 12

What is the main use of the gas N2O?

Answer 12

It is used as a mild anesthetic, also known as laughing gas.

Question 13

What are two kinds of nitrate ions involved in the nitrogen cycle?

Answer 13

Nitrate(III) ion and nitrate(V) ion.

Question 14

What is the formula of a nitrate(III) ion?

Answer 14

NO2-

Question 15

What is the formula of a nitrate(V) ion?

Answer 15

NO3-

Question 16

What is the sequence of nitrogen reduction from nitrate(V) ions, include the oxidation state at the bottom for each one?

Answer 16

NO3- → NO2- → NO → N2O → N2

(+5) (+3) (+2) (+1) (0)

Question 17

In both nitrate(III) and nitrate(V), how is the negative charge created?

Answer 17

By alternating double bonds, cause by the electrons being delocalized.

Question 18

When does the reduction of nitrogen sequence take place?

Answer 18

In conditions where oxygen content is low, anaerobic bacteria breaks it down.

Question 19

In what conditions are nitrate ions made?

Answer 19

When oxygen is available, made by oxidation of ammonium ions by aerobic bacteria.

Question 20

What is the process of making nitrates known as?

Answer 20

Nitrification.

Question 21

What is the equation for the first stage of nitrification for forming nitrate(III) ions?

Answer 21

NH4+(aq) + 1 1/2O2(g) → NO2-(aq) + 2H+(aq) + H2O(l)

Question 22

What is the equation for the second stage of nitrification where you oxidizing nitrate(III) ion further to nitrate(V) ions?

Answer 22

NO2-(aq) +1/2O2(g) → NO3-(aq)

Question 23

What are things used to test for nitrate(V) ions?

Answer 23

Sodium hydroxide solution and Devarda’s alloy, e.g. Cu, Al, Zn.

Question 24

What would be produced if solution contained Nitrate(V) ions?

Answer 24

Ammonia gas.

Question 25

Why is Devarda’s alloy required for the test?

Answer 25

It acts as a reducing agent.

Question 26

What is a test you can do for ammonia gas?

Answer 26

It turns damp red litmus paper blue.

Question 27

How can you test for ammonium ions?

Answer 27

Sodium hydroxide solution is added and gently heated, if ammonium ions are present, ammonia gas will form.