Two Experimental Runs Are Performed to Determine the Calorimetric Properties $- 10.0 ^ { \circ } \mathrm { C } .$

question 69

Multiple Choice

Two experimental runs are performed to determine the calorimetric properties of an alcohol which
has a melting point of $- 10.0 ^ { \circ } \mathrm { C } .$ In the first run, a 200-g cube of frozen alcohol, at the melting point,
is added to 300 g of water at $20.0 ^ { \circ } \mathrm { C }$ in a styrofoam container. When thermal equilibrium is
reached, the alcohol-water solution is at a temperature of $5.0 ^ { \circ } \mathrm { C }$ In the second run, an identical
cube of alcohol is added to 500 g of water at $20.0 ^ { \circ } \mathrm { C }$ and the temperature at thermal equilibrium is
$10.0 ^ { \circ } \mathrm { C }$ The specific heat capacity of water is $4190 \mathrm {~J} / \mathrm { kg } \cdot \mathrm { K } .$ Assume no heat is exchanged with the
styrofoam container and the surroundings. What is the heat of fusion of the alcohol?

• A)\(8.7 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }\)
• B) \(7.9 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }\)
• C) \(7.1 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }\)
• D) \(6.3 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }\)
• E) \(5.5 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }\)

---

Definitions:

Normal Model

A statistical model based on the Normal (or Gaussian) distribution, characterized by a symmetrical bell-shaped curve indicating data dispersion.

Presale Testing

An assessment process used by companies to evaluate the viability, market potential, or functionality of a product before it is launched to the public.

Random

The lack of pattern or predictability in events, often referring to a selection method where each item has an equal chance of being chosen.

Manic-Depressive Illness

Also known as bipolar disorder, a mental health condition characterized by extreme mood swings, including emotional highs (mania or hypomania) and lows (depression).