Answer:
-65.897°C.
Explanation:
- Adding solute to water causes depression of the boiling point.
- The depression in freezing point (ΔTf) can be calculated using the relation: <em>ΔTf = Kf.m,</em>
where, ΔTf is the depression in freezing point of chloroform solution.
Kf is the molal depression constant of chloroform (Kf = 4.70°C.kg/mol).
m is the molality of the solution (m = 0.51 m).
∴ ΔTf = Kf.m = (4.70°C.kg/mol)(0.51 m) = 2.397°C.
∴ The freezing point of the solution = (freezing point of chloroform) - ΔTf = (-63.5°C) - (2.397°C) = -65.897°C.
Answer:
(a) The system does work on the surroundings.
(b) The surroundings do work on the system.
(c) The system does work on the surroundings.
(d) No work is done.
Explanation:
The work (W) done in a chemical reaction can be calculated using the following expression:
W = -R.T.Δn(g)
where,
R is the ideal gas constant
T is the absolute temperature
Δn(g) is the difference between the gaseous moles of products and the gaseous moles of reactants
R and T are always positive.
- If Δn(g) > 0, W < 0, which means that the system does work on the surroundings.
- If Δn(g) < 0, W > 0, which means that the surroundings do work on the system.
- If Δn(g) = 0, W = 0, which means that no work is done.
<em>(a) Hg(l) ⇒ Hg(g)</em>
Δn(g) = 1 - 0 = 1. W < 0. The system does work on the surroundings.
<em>(b) 3 O₂(g) ⇒ 2 O₃(g)
</em>
Δn(g) = 2 - 3 = -1. W > 0. The surroundings do work on the system.
<em>(c) CuSO₄.5H₂O(s) ⇒ CuSO₄(s) + 5H₅O(g)
</em>
Δn(g) = 5 - 0 = 5. W < 0. The system does work on the surroundings.
<em>(d) H₂(g) + F₂(g) ⇒ 2 HF(g)</em>
Δn(g) = 2 - 2 = 0. W = 0. No work is done.
An ice cube when you heat it it can to water and water is liquid of course
Answer:
Heat energy is transferred to cooler objects to reduce the temperature of those objects.
Explanation:
The fourth option is not correct.
A correct way of writing it would be : " Heat energy is transferred from cooler objects to reduce the temperature of those objects.". When an object loses heat energy, its temperature reduces. Conversely, when an object receives heat energy, its temperature increases.