The correct answer would be the first option. Material A having a smaller latent heat of fusion would mean that it will take only less energy to phase change into the liquid phase. Latent of heat of fusion is the amount of energy needed of a substance to phase change from solid to liquid or liquid to solid.
The chemical reaction would be as follows:
<span>2Na + S → Na2S
We are given the amount of the reactants to be used in the reaction. We use these to calculate the amount of product. We do as follows:
45.3 g Na ( 1 mol / 22.99 g ) = 1.97 mol Na
105 g S ( 1 mol / 32.06 g ) = 3.28 mol S
The limiting reactant would be Na. We calculate as follows:
1.97 mol Na ( 1 mol Na2S / 2 mol Na ) (78.04 g / mol ) = 76.87 g Na2S produced</span>
Ivan Pavlov is most known for demonstrating conditioned lreflex in dogs.
<h3>what is conditioned reflex?</h3>
Conditioned reflex is a reflex action which has been conditioned to occur even without the stimulus which produces the reflex.
Ivan Pavlov is known to demonstrate conditioned reflex in dogs.
In his experiment, he trained dogs to salivate at the sound of a bell even if food which is the stimulus that produces salvation was not present.
Learn more about conditioned reflex at: brainly.com/question/24968947