Chemical reactions

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1. As seen on the movie clip on the right, the burning of fuel releases a great deal of energy as it reacts with oxygen. Which comment below is true?

A) It is obvious that this reaction is not a chemical reaction as no new product is formed. B) A new product(heat energy) is formed during this nuclear reaction. C) Neutrons are transferred between the fuel and the oxygen molecules giving off energy in the process. D) Atoms are separated and reassembled during this chemical reaction, giving off energy in the process. E) Protons are transferred between the fuel and the oxygen molecules giving off energy in the process.

2. Atom “X” has 12 electrons, 12 protons and 15 neutrons. This atom is most likely to:
A) have the electronic configuration 2,8,5 B) give up 10 electrons so that it can be as stable as helium. C) take electrons from other atoms in order to fill its outer energy level D) form an ion with a charge of +2; E) form an ion with a charge of -2

3. During a chemical reaction:
A) atoms or groups of atoms are rearranged to form new products. B) new atoms are formed. C) some atoms are destroyed to create new elements. D) new products are formed with the creation of new atoms. E) a colour change always occurs.

4. During some chemical reactions:
A) atoms decrease in atomic mass. B) atoms increase in atomic mass. C) electrons may be transferred from one atom to another. D) protons may be transferred from one atom to another. E) neutrons may be transferred from one atom to another.

5. The movie clip on the right shows zinc metal in an acid solution. From our observation we can confidently say that:
A) gas is been produced and therefore the reaction is an example of a chemical reaction. B) the temperature of the solution is slowly decreasing indicating that this is not a chemical reaction. C) this reaction is not a chemical reaction but a physical reaction. D) no new substance is being formed. E) None of the above are true.

6. When a mixture of oxygen and hydrogen is ignited, as happens during a launch of the Space Shuttle, water is formed and a great deal of energy is released. This is an example of a:
A) chemical reaction where water is the only new product formed, B) chemical reaction because the products from the reaction are not new, C) chemical reaction because energy is released and water is  formed and the process is irreversible, D) physical reaction because no new products are produced, E) physical reaction because the energy released is only a small amount.

7. Which of one of the following is not a sign of a chemical reaction?
A) Heat is produced. B) A gas is formed. C) A substance turns from a liquid to a solid. D) There is a colour change. E) Sound, light or electricity may be produced.

8. Two clear solutions are mixed together as shown on the right. Is this a chemical reaction?
A) This is a chemical reaction as indicated by the colour change. B) This is not a chemical reaction. C) This is a physical change. D) This is not a chemical reaction because no new product is formed. E) This is not a chemical reaction because no gas is formed.

9. Hydrocholic acid reacts with zinc metal to produce zinc chloride and hydrogen gas. Which comment below is true?
A) Hydrochloric acid is a product for this reaction. B) Zinc is a product for this reaction. C) Hydrochloric acid and zinc are the reactants. D) Hydrogen gas is a reactant. E) Zinc chloride is a reactant for this reaction.

10. When solid carbon dioxide, commonly known as dry ice, is placed in water it quickly turns into a gas. Which one comment below is true?
A) This is a physical change because a new substance is formed. B) This is a physical change because no new substance is formed. C) This is a chemical reaction because no new substance is formed. D) This is a chemical reaction because a new substance is formed. E) This is both a chemical reaction and a physical change.