Question

Question 1 (True/False Worth 2 points)
(04.03 LC)

When Pb and AlCl3 react together, lead (Pb) can replace aluminum (Al) in the compound because lead is lower on the activity series.

True
False
Question 2(Multiple Choice Worth 4 points)
(04.03 MC)

Which of the following equations has the correct products and is balanced correctly for a reaction between Na3PO4 and KOH?

Na3PO4 + 3KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction
Na3PO4 + KOH → Na3OH + KPO4, because K increases in charge from 1+ to 3+ when it is replaced
Na3PO4 + KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction
Na3PO4 + KOH → Na3OH + K3PO4, because K increases in charge from 1+ to 3+ when it is replaced
Question 3(Multiple Choice Worth 4 points)
(04.03 LC)

Which of the following is a single replacement reaction?

Ba(OH)2 + H2SO4 → BaSO4 + 2H2O
2Mg + O2 → 2MgO
H2O+ CO2 → H2CO3
Zn + H2SO4 → ZnSO4 + H2
Question 4(Multiple Choice Worth 4 points)
(04.03 MC)

Sodium metal reacts with water to produce hydrogen gas.

What best describes this reaction?

A single replacement reaction takes place because sodium is less reactive than hydroxide ions.
A double replacement reaction takes place because sodium is less reactive than hydroxide ions.
A double replacement reaction takes place because sodium is more reactive than hydrogen.
A single replacement reaction takes place because sodium is more reactive than hydrogen.
Question 5 (True/False Worth 2 points)
(04.03 LC)

A single replacement reaction is a reaction in which one element replaces a similar element within a compound.

True
False
Question 6(Multiple Choice Worth 4 points)
(04.03 MC)

The table shows the nature of reactants and products formed in a certain type of chemical reaction.


Nature of Reactants and Products
Reactants Products
Metal + Ionic compound Metal + Ionic compound


Which of the following is true about the type of chemical reaction?
It is a single replacement reaction, and the anions in the two ionic compounds are different.
It is a single replacement reaction, and the cations in the two ionic compounds are different.
It is a double replacement reaction, and the anions in the two ionic compounds are different.
It is a double replacement reaction, and the cations in the two ionic compounds are different.

Answer 1

1) Answer is: False.

Balanced chemical reaction: Pb + AlCl₃ → no reaction.

The reactivity series is a series of metals from highest to lowest reactivity. Metal higher in the reactivity series will displace another.

Aluminium (Al) is higher in activity series than lead (Pb).

That means aluminium (Al) is stronger reducing agent than lead and gives electrons easier.

This series are used to summarize information about the reactions of metals with acids or water, double displacement reactions (more reactive metals displace metals with lower reactivity) and the extraction of metals from their ores.

2) Answer is: Na3PO4 + 3KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction.

This chemical reaction is double displacement reaction - cations (K⁺ and Na⁺) and anions (PO₄³⁻⁻ and OH⁻) of the two reactants switch places and form two new compounds.

Na₃PO₄ is sodium phosphate.

KOH is potassium hydroxide.

NaOH is sodium hydroxide.

K₃PO₄ is potassium phosphate.

3) Answer is: Zn + H2SO4 → ZnSO4 + H2.

Single replacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

In this balanced chemical reaction zinc (Zn) replaces hydrogen (H).

Zinc changes oxidation number from 0 to +2 (this is oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

4) Answer is: A single replacement reaction takes place because sodium is more reactive than hydrogen.

Balanced chemical reaction:

2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g).

Single replacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

In this balanced chemical reaction sodium (Na) replaces hydrogen (H).

Sodium changes oxidation number from 0 to +1 (oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

5) Answer is: True.

For example, balanced chemical reaction:

Ca + 2HCl → H₂ + CaCl₂.

Reduction hald reaction: 2H⁺ + 2e⁻→ H₂.

Oxidation half reaction: Ca⁰ → Ca²⁺ + 2e⁻.

In this balanced chemical reaction calcium (Ca) replaces hydrogen (H).

In this chemical reaction, calcium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0).

6) Answer is: It is a single replacement reaction, and the cations in the two ionic compounds are different.

For example, balanced chemical reaction:  

Ba + MgSO₄ → BaSO₄(s) + Mg.

In this balanced chemical reaction barium (Ba) replaces magnesium (Mg), because barium is higher at activity series.

Sulfate anion (SO₄²⁻) is the same in two ionic compounds, but cations (Mg²⁺ and Ba²⁺) changes.

Single Displacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.