Chemical Reactions Quiz: MCQ Exam!

12 Questions | By Wilstar | Last updated: Dec 4, 2020 | Total Attempts: 9776

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1.

Which one of the following represents a physical change?
- A.
  
  Iron rusting
- B.
  
  Paper burning
- C.
  
  Water freezing
- D.
  
  Dynamite exploding
2.

.O {font-size:149%;} You can tell a chemical reaction because it always produces …
- A.
  
  A different substance
- B.
  
  Reactants
- C.
  
  A change of state
- D.
  
  Water
3.

Slide 5 To balance a chemical equation, you should change only the…
- A.
  
  Subscripts
- B.
  
  Coefficients
- C.
  
  Chemical formulas
- D.
  
  Location of the arrow
4.

Slide 6 .O {font-size:149%;} If iron combines with oxygen to make iron oxide, the reactants are…
- A.
  
  Iron oxide
- B.
  
  Iron and iron oxide
- C.
  
  Iron and oxygen
- D.
  
  Oxygen and iron oxide
5.

Slide 7 How many carbon atoms are there in C12H22O11?
- A.
  
  6
- B.
  
  12
- C.
  
  18
- D.
  
  45
6.

Slide 8 How many oxygen atoms are in the product of this equation: 2H2 + O2 --> 2H2O
- A.
  
  2
- B.
  
  4
- C.
  
  8
- D.
  
  12
7.

Slide 9 .O {font-size:149%;} Which one of the following is a chemical equation?
- A.
  
  Ice + heat --> water
- B.
  
  Iron + oxygen --> rust
- C.
  
  CO2
- D.
  
  C + O2 --> CO2
8.

.O {font-size:149%;} Balance the following equation: Ag + O2 --> Ag2O
- A.
  
  Put a 2 in front of Ag
- B.
  
  Add a subscript 2 to the end of Ag2O
- C.
  
  Add a 4 in front of Ag and a 2 in front of Ag2O
- D.
  
  Add a 2 in front of Ag and a 1 in front of Ag2O
9.

.O {font-size:149%;} In a chemical equation, the arrow means what?
- A.
  
  A reaction is happening.
- B.
  
  The two sides are equal.
- C.
  
  The products flow into reactants.
- D.
  
  The equation is balanced.
10.

.O {font-size:149%;} The reactants include 7 grams of C and 4 grams of O. What is the total amount of C and O in the products?
- A.
  
  7 grams
- B.
  
  4 grams
- C.
  
  11 grams
- D.
  
  None
11.

.O {font-size:149%;} Who first determined that the masses of the reactants and products must be the same?
- A.
  
  Pasteur
- B.
  
  Archimedes
- C.
  
  Galileo
- D.
  
  Lavoisier
12.

.O {font-size:149%;} If you try to balance an equation by changing subscripts you change…
- A.
  
  The number of molecules of product
- B.
  
  The identity of the compound
- C.
  
  The atomic number
- D.
  
  The mass of the reactants