Share Chemical reactions, Combustion, Oxidation, Fermentation
Save to Folder
True or False? Water can oxidize.
FALSE!
Fermentation is caused by: (A) Fungi ONLY / (B) Fungi and bacteria / (C) Bacteria ONLY / (D) None of these answers is correct.
B. Fermentation is caused by FUNGI AND BACTERIA.
What things produce combustion? (A) Fish, plants and petrol / (B) Natural gas, wood and plastic / (C) Electricity, Iron and paper / (D) Natural gas, wood petrol
D. Natural gas, wood and petrol
In fermentation, bacteria that produce lactic acid ________ food and makes it last __________. (A) Destroys... less time/ (B) preserves... Longer / (C) preserves... Less time / (D) destroys... Longer
B. Preserves food and makes it last longer
Metals and food oxidize when... (A) They are exposed to air / (B) They are exposed to water / (C) They are brought close to each other / (D) They are exposed to oxygen
A. They are exposed to air.
Chemical reactions occur around us _________. (A) Once every 5 billion years / (B) once every trimester / (C) all the time / (D) once a week.
C. All the time
What happens when a chemical reaction occurs? (A) The substance stays the same. / (B) The properties of a substance are changed. / ( C) The substance disappears / (D) Both B and C are correct
B. The properties of a substance are changed.
Combustion produces energy in the form of _______ and _______ (A) Water and carbon dioxide / (B) oxygen and gas / (C) heat and light / (D) wood and natural gas
(C) heat and light
True or false? During oxidation, metals react with carbon dioxide in the air to form rust.
FALSE: Metals react with oxygen to form rust!
What material DOESN'T make food oxidize? (From class experiment) (A) Sugar / (B) orange juice / (C) flour / (D) oil
C. Flour
Combustion is... (A) Exothermic - produces heat / (B) Endothermic - absorbs heat / (C) Exothermic - surroundings get hotter / (D) Both A and C are correct.
D. Both A and C are correct.
When a chemical reaction occurs, it... (A) Produces the same things / (B) changes the properties of a substance / (C) Produces something different / (D) destroys things / (E) both B and C
Both B and C are correct
Combustion produces energy... (A) When water turns to ice / (B) When oxygen in the air reacts with wood, petrol and gas / (C) When ethanol and water mix / (D) when a gas turns into a solid.
B. When oxygen in the air reacts with wood, petrol and gas
Combustion = ____________ + ____________ (A) water + sugar / (B) Oxygen + fuel (wood, petrol, gas) / (C) Air + sunlight / D. Oxygen + air
B. Oxygen + fuel (wood, petrol, natural gas)
In a chemical reaction, energy is either ________ or _________ (A) absorbed or released / (B) digested or breathed / (C) eaten or drunk / (D) None of the above answers is correct
A. Energy is either absorbed or released.
TRUE OR FALSE: When wood burns, it produces oxygen..
False: it produces carbon dioxide
