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

question 189

Multiple Choice

A substance has a melting point of 20°C and a heat of fusion of $3.6 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }$ The boiling point is $150 ^ { \circ } \mathrm { C }$ and the heat of vaporization is $7.2 \times 10 ^ { 4 } \mathrm {~J} / \mathrm { kg }$ 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 given up by $2.80 \mathrm {~kg}$ of this substance when it is cooled from 170°C to 86°C at a pressure of one atmosphere?

• A)400 kJ
• B)200 kJ
• C)300 kJ
• D)440 kJ
• E)640 kJ

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Definitions:

Tend-and-Befriend Response

A behavior pattern where individuals provide care and protection under stressful situations, enhancing group safety and reducing vulnerability.

Fight-or-Flight Response

A physiological reaction to a perceived harmful event, attack, or threat to survival, preparing the body for rapid action.

Alarm Stage

The initial reaction of the body's stress response system, involving the activation of the sympathetic nervous system and the release of stress hormones.

Type A Behavior

A personality trait characterized by high levels of competitiveness, self-imposed stress, impatience, and aggression.