Mass of KCl= 1.08 g
<h3>Further explanation</h3>
Given
1 g of K₂CO₃
Required
Mass of KCl
Solution
Reaction
K₂CO₃ +2HCl ⇒ 2KCl +H₂O + CO₂
mol of K₂CO₃(MW=138 g/mol) :
= 1 g : 138 g/mol
= 0.00725
From the equation, mol ratio K₂CO₃ : KCl = 1 : 2, so mol KCl :
= 2/1 x mol K₂CO₃
= 2/1 x 0.00725
= 0.0145
Mass of KCl(MW=74.5 g/mol) :
= mol x MW
= 0.0145 x 74.5
= 1.08 g
Answer: A) This reaction will be spontaneous only at high temperatures
Explanation:
= +ve, reaction is non spontaneous
= -ve, reaction is spontaneous
= 0, reaction is in equilibrium
Using Gibbs Helmholtz equation:
Given : 
Thus the value of is negative and spontaneous when temperature is high.
When temperature of liquid is increased, liquid gets thinner and thinner and hence it's viscosity decreases.
Density = mass/volume.
As we increase the temperature, volume of the liquid starts to increase but mass of the liquid remains constant. As a result, density of liquid decreases.
Hope this helps!
