Question

The elements K and Cl react directly. What remains in the reaction vessel after equal masses of K and Cl2 have reacted until one or both of the reactants have been completely consumed?

Answer 1

In the reaction between equal masses of potassium (K) and chlorine gas (Cl₂), chlorine will be the limiting reactant and potassium the excess reactant, resulting in potassium chloride and unreacted potassium remaining in the reaction vessel.

Step-by-step explanation:

When potassium (K) reacts with chlorine gas (Cl₂), they form potassium chloride (KCl) through a chemical reaction. The reaction between potassium and chlorine is:

2 K(s) + Cl₂(g) → 2 KCl(s)

This balanced chemical equation shows that two atoms of potassium react with one molecule of chlorine gas to produce two units of potassium chloride. If equal masses of K and Cl₂ are used, one of the reactants will be completely consumed first, and this reactant is known as the limiting reactant. Since the atomic mass of potassium is much less than the molecular mass of chlorine gas, in equal masses, there will be more moles of potassium than chlorine gas. Hence, chlorine will be the limiting reactant, and potassium will be the excess reactant. After the reaction, the vessel will contain potassium chloride and some unreacted potassium, as not all the potassium will have reacted with chlorine gas.

Answer 2

In the reaction between potassium (K) and chlorine (Cl2), either one of them could be the limiting reactant if equal masses of K and Cl2 are reacted. The substance that remains in the reaction vessel will be the excess reactant, which is the reactant that is not completely consumed.

Step-by-step explanation:

The balanced equation for the reaction between potassium (K) and chlorine (Cl2) is 2K + Cl2 → 2KCl. This equation shows that 2 moles of potassium react with 1 mole of chlorine to produce 2 moles of potassium chloride. If equal masses of K and Cl2 are reacted until one or both of the reactants are completely consumed, then the limiting reactant will be the one that is completely consumed first. In this case, since the masses of K and Cl2 are equal, either one of them could be the limiting reactant. The substance that remains in the reaction vessel would be the excess reactant, which is the reactant that is not completely consumed.