Answer:
Ammonium chloride has ammonium (NH4 +) part which is slightly acidic and Barium Hydroxide is a strong base.
You can see that an acid-base reaction will occur.
In this case :
Its highly endothermic reaction
Forms aqueous ammonia (mind that ammonia is highly water soluble gas so no effervesence) and Barium Chloride which is water soluble.
Ba(OH)2 +NH4Cl ——->BaCl2 + NH3 +H2O (unbalanced)
Double replacement.
Ba(OH)2 + H2SO4 ====> 2H2O + BaSO4
I believe the answer is compound B may have a lower molecular weight compared to compound A.
At the same temperature, lighter particles of a compound have a higher average speeds than do heavier particles of another compound. Thus, particles of compound B are lighter than those of compound A and thus they have a higher average speed, hence evaporating faster compared to compound A.
