Answer:
1) <em>The correct answer is A. Collision</em>
2) A hot solvent helps a solid dissolve faster because an increase in <u><em>kinetic energy</em></u> that also increases the rate of collisions
Explanation:
When a solute is added into a solvent and stirred, the solute particles get distributed to all parts of the solvent as a result of stirring.
More collisions occur between the solute and the solvent due to stirring. This increases the rate of dissolving.
<em>When a solvent is heated, then the kinetic energy would increase and the atoms will collide with a much greater force. As a result, ore solute will be able to dissolve in the solvent. </em>
Al2(SO4)3 + 3Ca(OH)2 -> 2Al(OH)3 + 3Ca(SO)4
<h3>Balanced equation :
2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)</h3><h3>Further explanation</h3>
Alkanes are saturated hydrocarbons that have single bonds in chains
General formula for alkanes :

Hydrocarbon combustion reactions (specifically alkanes)

So that the burning of ethane with air (oxygen):

2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)
or we can use mathematical equations to solve equilibrium chemical equations by giving the coefficients for each compound involved in the reaction
C₂H₆ (g) + aO₂ (g) ⟶ bCO₂ (g) + cH₂O (ℓ)
C : left 2, right b ⇒ b=2
H: left 6, right 2c⇒ 2c=6⇒ c= 3
O : left 2a, right 2b+c⇒ 2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2