science - changes/combustion

Question 1

chemical change

Answer 1

breaking or making bonds. Irreversible. New product is made.

Question 2

Physical change

Answer 2

might change its physical state but it is still the exact same

Question 3

what is the law of conservation?

Answer 3

mass cant be created or destroyed - total ass of reactant is the same as the mass of the new product

Question 4

what does combustion mean?

Answer 4

another way to say burning. Reaction of fuels with oxygen that transfers thermal energy

Question 5

what is complete combustion?

Answer 5

there is alot of oxygen - produces water and carbon dioxide. Occurs when there is alot of oxygen which allows the fuel to react with so it produces carbon dioxide

Question 6

what is incomplete combustion?

Answer 6

there is limited oxygen - produces water and monoxide (soot). Occurs when there isnt enough oxygen for the fuel to react with so it doesnt produce carbon dioxide.

Question 7

what is the formula for completed combustion?

Answer 7

hydrocarbon + oxygen = water + carbon dioxide

Question 8

what is the formula for incomplete combustion?

Answer 8

hydrocarbon + oxygen = water + carbon monoxide + carbon

Question 9

Why is carbon monoxide bad?

Answer 9

1 - it is a poisonous gas
2 - it is soot, soot is a fine black powder that can irritate the lungs and the air ways
3 - has no taste or smell.