5.1: Synthesis and Decomposition Reactions

Question 1

Evidence of chemical change

Answer 1

• formation of a precipitate
• change in colour
• formation of a gas
• change in odour
• production of light
• production of heat

Precious, Come Here [to] GOLlum

Question 2

Synthesis reaction

Answer 2

a + b -> ab

the reaction may be any combination of elements and compounds, but the products will always be a compound

Question 3

states of HOFBrINCl

Answer 3

all gases
EXCEPT bromine (liquid) and iodine (solid)

Question 4

synthesis reaction to produce ammonia

Answer 4

the haber process

synthesis of Nitrogen and Hydrogen (NH[sub3]+)

Question 5

uses of ammonia

Answer 5

• fertilizer (because of the nitrogen)
• making paper
• extracting zinc and nickel from ores
• explosives
• cleaning products

Question 6

synthesis reaction to produce atmospheric pollutants

Answer 6

nitrogen gas in the atmosphere reacts with oxygen to produce nitrogen oxides

Question 7

decomposition reaction

Answer 7

ab -> a + b

Question 8

produce hydrogen gas through decomposition

Answer 8

electrolysis of water

electric current used to break apart bonds between the H and the O

Question 9

explosives through decomposition

Answer 9

decomposition of a compound and the rapid heating and expansion of the gases that are produced

Question 10

airbags

Answer 10

decomposition of sodium azide (NaN[sub3]) to produce hydrogen gas, which rapidly inflates the bag. the decomposition reaction is triggered by heating to around 300 C (which is what happens when a car gets into an accident). However, we don’t use it anymore (too dangerous, highly reactive with metal, water, etc)