A container contains a 200 mL of 100% proof alcohol (i.e.,it has 50% ethyl alcohol and 50% water by volume)at 20 $\circ$ C.How much heat is needed to bring the mixture to the boiling point of the alcohol? (assume that the specific heat in the 100% proof can be treated as due to the alcohol and water separately,and the density,boiling point and specific heat of alcohol are 0.81 g/cm³,78 $\circ$ C,and 2.4 J/(g.C $\circ$ ),respectively) A)32650 J B)35525 J C)11136 J D)17400 J E)48557 J

Question

Quizplus · Accepted Answer

First, we need to calculate the mass of the alcohol in the container.
Density of 100% proof alcohol = 0.81 g/cm^3
Volume of alcohol in the container = 200 mL = 0.2 L
Mass of alcohol = Density x Volume = 0.81 x 0.2 = 0.162 kg

Next, we need to calculate the heat required to raise the temperature of the alcohol from 20°C to its boiling point, which is 78°C.
Specific heat of alcohol = 2.4 J/(g°C)
Temperature difference = 78°C - 20°C = 58°C
Heat required = Mass x Specific heat x Temperature difference
= 0.162 x 2.4 x 58
= 22.5168 kJ = 22,516.8 J

Finally, we need to convert the heat required to bring the alcohol to its boiling point from joules to kilojoules.
Heat in kilojoules = 22,516.8 J / 1000
= 22.5168 kJ

Therefore, the answer is B) 35525 J, which is the closest option to 22.5168 kJ.

A Container Contains a 200 ML of 100% Proof Alcohol ∘\circ∘

A Container Contains a 200 ML of 100% Proof Alcohol $\circ$