Year 9 Science Chemistry 2
This is to be taken after studying the year 9 topic chemistry 2.
- 1.
Which of the following is an example of a chemical change?
- A.
A hot dog is cooked
- B.
Melting butter
- C.
Water is boiled
- D.
Old ham goes bad
Correct Answer
D. Old ham goes badExplanation
Ham's atoms are reacting to form a new substance, all the rest are reversible (hot dog is just warmed, state of butter and water is just changed)Rate this question:
-
- 2.
Check which of the following are examples of physical change.
- A.
A nail rusts in water.
- B.
Freezing water
- C.
Dissolving aspirin.
- D.
Cooking an egg.
Correct Answer(s)
B. Freezing water
C. Dissolving aspirin.Explanation
The other two (rust and egg) involve change of atoms.Rate this question:
-
- 3.
A chemical change is the formation of at least one new substance.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
A chemical change involves the creation of new substances with different chemical properties. This can occur through various processes such as a reaction between two or more substances, the breakdown of a compound into its components, or the rearrangement of atoms within a molecule. In contrast, a physical change does not result in the formation of new substances, but rather alters the state or appearance of a material. Therefore, the statement that a chemical change involves the formation of at least one new substance is true.Rate this question:
-
- 4.
A chemical change is easily reversible.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
A chemical change is difficult to reverse where as a physical change is easily reversible.Rate this question:
-
- 5.
Which of the following are not indications of chemical change.
- A.
Gas evolved.
- B.
Odour produced.
- C.
State change.
- D.
Fizzing.
- E.
New solid is formed.
- F.
Reactants solidify.
- G.
Colour change.
- H.
Temperature change.
- I.
Solid disappears.
Correct Answer(s)
C. State change.
F. Reactants solidify.Explanation
State change and reactants solidifying are not indications of chemical change because they are physical changes. In a state change, the substance transitions from one state of matter to another (e.g. from solid to liquid or gas), but its chemical composition remains the same. Reactants solidifying refers to a substance returning to a solid state, but this does not involve a chemical reaction. Chemical changes, on the other hand, involve the formation of new substances with different chemical properties.Rate this question:
-
- 6.
In a chemical reaction new atoms are formed.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
In a chemical reaction new atoms are not formed or created but the existing atoms are rearranged into new substances.Rate this question:
-
- 7.
The Law of Conservation of Mass states: matter can neither be c____ or destroyed during a chemical reaction.
Correct Answer
created, CreatedExplanation
The Law of Conservation of Mass is a fundamental principle in chemistry, stating that matter cannot be created or destroyed in a chemical reaction. This means that the total mass of reactants before the reaction equals the total mass of the products after the reaction. While the substances involved may change form, the amount of matter remains constant, ensuring that mass is conserved throughout the process. This law is crucial for understanding chemical equations.Rate this question:
- 8.
The Law of Constant Proportion states that:
- A.
Matter can neither be created or destroyed in a chemical reaction.
- B.
A molecule, regardless of its components, will always have equal amounts of all elements.
- C.
Metals and non-metals, when the products of a reaction, will always be in equal quantities.
- D.
A compound, no matter how it is formed, always contains the same relative amounts of each element.
- E.
Oxygen and carbon are always in proportional ratios in the earth's atmosphere.
Correct Answer
D. A compound, no matter how it is formed, always contains the same relative amounts of each element.Explanation
The Law of Constant Proportion states that a compound, no matter how it is formed, always contains the same relative amounts of each element. This means that the ratio of elements in a compound is always constant, regardless of the method used to create the compound. For example, if a compound is made up of elements A and B, it will always have the same ratio of A to B, regardless of whether it is formed through a chemical reaction or any other means. This law helps to explain the consistent composition of compounds and allows chemists to predict the amounts of elements present in a compound.Rate this question:
-
- 9.
Which of the following are examples of a combustion reaction.
- A.
Burning petrol.
- B.
Natural gas in stove.
- C.
Zinc rusting.
- D.
Methane burning in a gas jet.
- E.
Zinc Carbonate decomposing.
- F.
Sodium hydroxide and hydrochloric acid reacting.
Correct Answer(s)
A. Burning petrol.
B. Natural gas in stove.
D. Methane burning in a gas jet.Explanation
zinc rusting is corrosion, zinc carbonate decopmosing is decompostion and sodium hyrdoxide with acid is a neutralisation reaction.Rate this question:
-
- 10.
Exothermic reaction involves the release of heat.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Endothermic involves the absorption of heat.Rate this question:
-
- 11.
A c______ reaction is when substances react with o_____ to release h___.
Correct Answer
combustion, oxygen, heat
combustion oxygen heat
ombustion, xygen, eat
ombustion xygen eatExplanation
A combustion reaction is when substances react with oxygen to release heat.Rate this question:
- 12.
In combustion reactions hyrdocarbons combine with nitrogen in the air to form carbon dioxide gas and nitrogen hydroxide.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
In combustion reactions hyrdocarbons combine with oxygen in the air to form carbon dioxide gas and water vapour.Rate this question:
-
- 13.
A corrosion reaction is ....
- A.
When carbon dioxide causes an object to implode.
- B.
Ham forming mould.
- C.
Where a metal is 'eaten away' by substances in the air or water.
- D.
When a liquid evaporates due to a reaction with a transitional metal.
Correct Answer
C. Where a metal is 'eaten away' by substances in the air or water.Explanation
A corrosion reaction refers to the process where a metal is gradually deteriorated or "eaten away" by substances present in the air or water. This happens due to chemical reactions between the metal and the corrosive substances, which can lead to the formation of rust or other forms of corrosion on the metal surface. Carbon dioxide causing an object to implode, ham forming mold, and liquid evaporation due to a reaction with a transitional metal are unrelated to corrosion reactions.Rate this question:
-
- 14.
G______ is when m_____ are protected by z____ to stop reacting with w____ and o_____. (no punctuation or capitals)
Correct Answer
galvanising metal zinc water oxygen
alvanising etal inc ater xygen
galvanising metals zinc water oxygen
alvanising etals inc ater xygen
galvanisation metal zinc water oxygen
alvanisation etal inc ater xygen
galvanisation metals zinc water oxygen
alvanisation etals inc ater xygenExplanation
Galvanising is the process of coating metal with zinc to protect it from reacting with water and oxygen. This process forms a protective layer on the metal surface, preventing corrosion and extending its lifespan.Rate this question:
- 15.
Zinc reacts with oxygen to form zinc oxide.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
an example of a corrosion reaction.Rate this question:
-
- 16.
Zinc breaking down into zinc oxide and carbon dioxide is an example of a....
- A.
Corrosion reaction.
- B.
Decomposition reaction.
- C.
Combustion reaction.
Correct Answer
B. Decomposition reaction.Explanation
Zinc breaking down into zinc oxide and carbon dioxide is an example of a decomposition reaction. In this reaction, a single compound (zinc) is broken down into two or more simpler substances (zinc oxide and carbon dioxide). This is different from a corrosion reaction, which involves the gradual deterioration of a material due to chemical reactions with its environment, and from a combustion reaction, which involves the rapid reaction of a substance with oxygen, typically resulting in the release of heat and light.Rate this question:
-
- 17.
When naming compounds a non-metal goes before a metal.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
When naming compounds a metal goes before a non-metal.Rate this question:
-
Quiz Review Timeline +
Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
-
Current Version
-
Aug 12, 2024Quiz Edited by
ProProfs Editorial Team -
Oct 04, 2011Quiz Created by
Bec_c