Question

Which of the following, when dissolved, will cause water to reach the highest temperature before boiling?

A. Epsom Salt (MgSO4)
B. Potassium sulfide (K2S)
C. Sodium Chloride (NaCl)
D. Sugar (C6H12O6)

Answer 1

Potassium sulfide (K2S)

Step-by-step explanation:

Answer via Founder's Education/Educere

Answer 2

B

Step-by-step explanation:

The boiling point of water increases when a solute is dissolved in the water. The amount by which the boiling point is raised depends on the number of solute particles in the water.

For equal molar quantities of Epsom salt, potassium sulfide, sodium chloride, and sugar are, potassium sulfide yields the most particles.

K₂S dissociates as follows:

K₂S ⇒ 2K⁺ + S²⁻

One mole of K₂S yields 3 moles of particles.

Epsom salt (MgSO₄) yields 2 moles of particles for every mole:

MgSO₄ ⇒ Mg²⁺ + SO₄²⁻

Sodium chloride (NaCl) also yields 2 moles of particles for every mole:

NaCl ⇒ Na⁺ + Cl⁻

Sugar is not an electrolyte and does not dissociate, so 1 mole of sugar produces 1 mole of solute particles.