A Substance Has a Melting Point of 20°C and a Heat

question 32

Multiple Choice

A substance has a melting point of 20°C and a heat of fusion of 3.4 × $10^4$ J/kg. The boiling point is $150 ^ { \circ } \mathrm { C }$ and the heat of vaporization is $6.8 \times 10^4 \mathrm {~J} / \mathrm { kg }$ at a pressure of one atmosphere. The specific heats for the solid, liquid, and gaseous phases are 600 J/kg ∙ K (solid) , 1000 J/kg ∙ K (liquid) , and 400 J/kg ∙ K (gaseous) . How much heat is required to raise the temperature of $1.90 \mathrm {~kg}$ of this substance from $- 4 ^ { \circ } \mathrm { C }$ to $106 ^ { \circ } \mathrm { C }$ at a pressure of one atmosphere?

• A) 260 kJ
• B) 190 kJ
• C) 230 kJ
• D) 92 kJ
• E) 320 kJ

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Definitions:

Present Value Factor

A factor used to calculate the present value of a future amount of money or stream of cash flows given a specific rate of return.

Straight-Line Depreciation

A process of dividing the expense of a substantial asset into identical annual portions over its useful duration.

Net Income

The net income of a firm after deducting all expenses and taxes from its gross revenue.

Cash Payback Period

A rephrased term for Payback Period, this is the duration required for an investment to generate cash flows that cover its initial expense.