The Freezing Point of Ammonia (NH₃, 17 $\degree$ CIn an Experiment, 367

question 72

Multiple Choice

The freezing point of ammonia (NH₃, 17.04 g/mol) is -77.73 $\degree$ C.In an experiment, 367.2 grams of solid NH₃ at-77.73 $\degree$ C is used to cool 250.0 grams of liquid NH₃ from 25.00 $\degree$ C to the freezing point.Assume that the specific heat capacity of liquid NH₃ is 4.742 J/(g . $\degree$ C) .What is the enthalpy of fusion of ammonia?

• A)2.894 kJ/mol
• B)(-2.894 kJ/mol)
• C)5.652 kJ/mol
• D)(-5.652 kJ/mol)
• E)0.3315 kJ/mol

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Definitions:

Homology

Refers to the existence of shared ancestry between a pair of structures, or genes, in different species.

Parsimonious

Characterized by extreme or excessive economy or simplicity in approach or methodology, often in scientific theories.

Convergent Evolution

A process whereby organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

Homologous

Referring to genes, chromosomes, or structures that are similar in position, structure, and evolutionary origin, but not necessarily in function.