<u>Answer:</u> The chemical equation is written below.
<u>Explanation:</u>
Every balanced chemical equation follows law of conservation of mass.
This law states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form. This also means that total number of individual atoms on reactant side must be equal to the total number of individual atoms on the product side.
The chemical equation for the reaction of elemental boron and oxygen gas follows:

By Stoichiometry of the reaction:
4 moles of elemental boron reacts with 3 moles of oxygen gas to produce 2 moles of diboron trioxide.
The chemical equation for the reaction of diboron trioxide and water follows:

By Stoichiometry of the reaction:
1 mole of diboron trixoide reacts with 3 moles of water to produce 2 moles of boric acid.
Hence, the chemical equations are written above.
Answer:
0.07 g/s.
Explanation:
From the question given above, the following data were obtained:
Mass lost = 9.85 g
Time taken = 2 min 30 s
Mean rate =?
Next, we shall convert 2 min 30 s to seconds (s). This can be obtained as follow:
1 min = 60 s
Thus,
2 min = 2 × 60 = 120 s
Therefore,
2 min 30 s = 120 s + 30 s = 150 s
Finally, we shall determine the mean rate of the reaction. This can be obtained as illustrated below:
Mass lost = 9.85 g
Time taken = 150 s
Mean rate =?
Mean rate = mass lost / time taken
Mean rate = 9.85 / 150
Mean rate = 0.07 g/s
Therefore, the mean rate of the reaction is 0.07 g/s
The volume of H₂ evolved at NTP=0.336 L
<h3>Further explanation</h3>
Reaction
Decomposition of NH₃
2NH₃ ⇒ N₂ + 3H₂
conservation mass : mass reactants=mass product
0.28 NH₃= 0.25 N₂ + 0.03 H₂
2 g H₂ = 22.4 L
so for 0.03 g :

Answer is: this is an example of an Arrhenius acid.
An Arrhenius acid is a
substance that dissociates in water to form hydrogen ions or protons (H⁺).
For example hydrochloric acid: HCl(aq) → H⁺(aq) + Cl⁻(aq).
An Arrhenius base is a
substance that dissociates in water to form hydroxide ions (OH⁻<span>).
In this example lithium hydroxide is an Arrhenius base:</span>
LiOH(aq) → Li⁺(aq) + OH⁻(aq).