01
True or false
1 point
True or false: In a chemical equation, the arrow means that the reactants yield or form the products.
Free Practice Quiz Question List
4 Chemical Reactions and Equations Online Quiz Questions
Use this free practice quiz with 20 questions to review 4 Chemical Reactions and Equations, test your knowledge, and prepare for your next test or exam.
20 questions
02
Written response
1 point
In a chemical equation, what does the state symbol (aq) indicate about a substance?
03
Choose one
1 point
The reaction 2Mg + O₂ → 2MgO combines magnesium and oxygen to form one compound. Which reaction pattern does it illustrate?
- A
Decomposition
- B
Synthesis
- C
Single replacement
- D
Double replacement
04
True or false
1 point
True or false: To balance a chemical equation, you may change a formula's subscripts as well as its coefficients.
- A
True
- B
False
05
Fill in the blank
1 point
According to the complete-combustion pattern for a hydrocarbon, the products are and .
06
Choose one
1 point
Classify the reaction Zn + 2HCl → ZnCl₂ + H₂.
- A
Synthesis
- B
Decomposition
- C
Single replacement
- D
Combustion
07
True or false
1 point
True or false: In a closed system, the total mass of the reactants equals the total mass of the products in an ordinary chemical reaction.
- A
True
- B
False
08
Written response
1 point
In the equation 4Al + O₂ → 2Al₂O₃, what smallest whole-number coefficient must be placed before O₂ to balance the equation?
09
Choose all
1 point
For AgNO₃ + NaCl → AgCl(s) + NaNO₃, select all statements that correctly describe the reaction.
- A
The reactants are two compounds.
- B
An element replaces an element in a compound.
- C
The compounds exchange partners.
- D
The products are two compounds.
10
Fill in the blank
1 point
Complete the balanced equation using the smallest whole-number coefficients: N₂ + H₂ → NH₃.
11
Choose one
1 point
Which reaction pattern is shown by 2H₂O₂ → 2H₂O + O₂?
- A
Synthesis
- B
Decomposition
- C
Double replacement
- D
Combustion
12
Choose all
1 point
Select all statements that describe valid steps or checks when balancing a chemical equation.
- A
Change coefficients rather than subscripts.
- B
Count each element's atoms on both sides.
- C
Change a formula's subscripts to make the counts match.
- D
Reduce the coefficients to the smallest whole-number ratio.
13
Open ended
1 point
Balance Al + O₂ → Al₂O₃ using the smallest whole-number coefficients. Then explain how your equation shows equal atom counts without changing the substances' formulas.
14
Choose one
1 point
In a chemical equation, what does the state symbol (aq) indicate?
- A
A solid substance
- B
A substance dissolved in water
- C
A liquid substance
- D
A gas
15
Choose one
1 point
Which pair of products is expected from the complete combustion of a hydrocarbon?
- A
Carbon monoxide and hydrogen
- B
Carbon and water
- C
Carbon dioxide and water
- D
Carbon dioxide only
16
Choose one
1 point
How is the reaction Zn + 2HCl → ZnCl₂ + H₂ classified?
- A
Single replacement
- B
Synthesis
- C
Decomposition
- D
Double replacement
17
Choose one
1 point
Which equation is an example of synthesis?
- A
2H₂O₂ → 2H₂O + O₂
- B
AgNO₃ + NaCl → AgCl + NaNO₃
- C
Zn + 2HCl → ZnCl₂ + H₂
- D
2Mg + O₂ → 2MgO
18
Choose one
1 point
When balancing a chemical equation, which adjustment preserves the identity of each substance while changing its atom count contribution?
- A
Change subscripts, because they only affect atom counts.
- B
Change coefficients, because they multiply the entire formula.
- C
Change the element symbols to conserve matter.
- D
Change the arrow to show the required atom ratio.
19
Written response
1 point
When N₂ + H₂ → NH₃ is balanced with the smallest whole-number coefficients, what coefficient belongs before H₂?
20
Written response
1 point
What reaction pattern describes AgNO₃ + NaCl → AgCl(s) + NaNO₃?