Chemical Changes Assessment Gizmos Exam
Questions and Correct Answers
1. A white powder is added to a solution. The images show observations
made before the powder is added, just after the powder has been
added, and a little while later. (The liquid in the small beaker is phenol
red solution.) What evidence shows that a chemical change has taken place?
correct answer: Correct Answer correct answer: D. All of the above.
2. A reaction produces a gas, which is collected in a glass cylinder.
When a glowing splint is placed inside the container, it burns
brightly, as shown. Which gas was produced in the reaction? correct
answer: Correct Answer correct answer: B. Oxygen
3. A chemical reaction is done in the setup shown, resulting in a change
of mass. What will happen if the same reaction is done in a sealed
container that is placed on the electronic balance? correct answer: Correct Answer
correct answer: B. The mass will stay the same because the gases produced in the reaction
are kept inside the container.
4. Based on its formula, what type of chemical reaction occurs
between silver nitrate (AgNO3) and copper (Cu)?
2AgNO3 + Cu ’2Ag + Cu(NO3)2 correct answer: Correct Answer correct answer: C.
Single replacement
5. When hydrogen peroxide (H2O2) is added to potassium iodide (KI)
solution, the hydrogen peroxide decomposes into water (H2O) and
oxygen (O2). The chemical equation for this decomposition
reaction is correct answer:
2H2O2 ’2H2O + O2 correct answer: Correct Answer correct answer: D. Catalyst
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Questions and Correct Answers
1. A white powder is added to a solution. The images show observations
made before the powder is added, just after the powder has been
added, and a little while later. (The liquid in the small beaker is phenol
red solution.) What evidence shows that a chemical change has taken place?
correct answer: Correct Answer correct answer: D. All of the above.
2. A reaction produces a gas, which is collected in a glass cylinder.
When a glowing splint is placed inside the container, it burns
brightly, as shown. Which gas was produced in the reaction? correct
answer: Correct Answer correct answer: B. Oxygen
3. A chemical reaction is done in the setup shown, resulting in a change
of mass. What will happen if the same reaction is done in a sealed
container that is placed on the electronic balance? correct answer: Correct Answer
correct answer: B. The mass will stay the same because the gases produced in the reaction
are kept inside the container.
4. Based on its formula, what type of chemical reaction occurs
between silver nitrate (AgNO3) and copper (Cu)?
2AgNO3 + Cu ’2Ag + Cu(NO3)2 correct answer: Correct Answer correct answer: C.
Single replacement
5. When hydrogen peroxide (H2O2) is added to potassium iodide (KI)
solution, the hydrogen peroxide decomposes into water (H2O) and
oxygen (O2). The chemical equation for this decomposition
reaction is correct answer:
2H2O2 ’2H2O + O2 correct answer: Correct Answer correct answer: D. Catalyst
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