Why does NH₃ have a much higher boiling point than PH₃?
Correct answer D. NH₃ molecules are linked by hydrogen bonds
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MDCAT ECAT Chemistry MCQs
Page 35 of MDCAT ECAT Chemistry multiple-choice questions with answers. Tap an option to check yourself.
Page 35 of 39
- Gases 40
- Liquids 40
- Solids 40
- Chemical Equilibrium 40
- Reaction Kinetics 40
- Thermochemistry and Energetics 40
- Electrochemistry 40
- Fundamental Concepts of Chemistry 40
- Atomic Structure 39
- Chemical Bonding 39
- Alcohols and Phenols 38
- Industrial Chemistry 37
- Aldehydes and Ketones 37
- Alkyl Halides 37
- s- and p-Block Elements 37
- Chemistry of Hydrocarbons 36
- Fundamental Principles of Organic Chemistry 36
- Carboxylic Acids 36
- Transition Elements 35
- Macromolecules 35
Which of the following is the strongest individual hydrogen bond?
Correct answer C. F–H···F
Which compound cannot form hydrogen bonds between its own molecules?
Correct answer B. H₂S
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At what temperature does liquid water have its maximum density?
Correct answer D. 4 °C
Why does ice float on liquid water?
Correct answer C. Hydrogen bonding gives ice an open cage structure with empty spaces
How does aquatic life survive in a lake whose surface has frozen in winter?
Correct answer B. Water at 4 °C is densest and stays at the bottom, below the floating ice
Which two assumptions of the kinetic molecular theory fail for real gases at high pressure and low temperature?
Correct answer A. Molecular volume is negligible and there are no intermolecular attractions
For an ideal gas, the compressibility factor Z = PV/nRT is ____
Correct answer A. equal to 1 at all pressures
Which gas is expected to behave most nearly like an ideal gas?
Correct answer B. He
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In the van der Waals equation, the term an²/V² corrects for ____
Correct answer B. intermolecular attractive forces
A gas occupies 500 cm³ at 760 mm Hg. At constant temperature, what is its volume at 950 mm Hg?
Correct answer C. 400 cm³
According to the kinetic molecular theory, the pressure of a gas is caused by ____
Correct answer D. collisions of molecules with the walls of the container
What is −73 °C expressed on the Kelvin scale?
Correct answer C. 200 K
A gas occupies 2.0 dm³ at 1.0 atm and 273 K. What is its volume at 2.0 atm and 546 K?
Correct answer D. 2.0 dm³
From the ideal gas equation, how does the density of a gas change?
Correct answer B. It increases with pressure and decreases with temperature
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For a fixed mass of an ideal gas at constant temperature, how does the product PV vary as pressure increases?
Correct answer C. It remains constant
According to the kinetic molecular theory, liquids have a definite volume but no definite shape because their molecules ____
Correct answer B. are close together but can slide past one another
Why is diffusion much slower in liquids than in gases?
Correct answer C. Liquid molecules are close together and attract each other strongly
At constant pressure, a gas volume plotted against Celsius temperature gives a straight line. When extended, this line meets the temperature axis at about ____
Correct answer D. −273 °C
According to Charles’s law, at constant pressure the volume of a gas changes per degree Celsius by what fraction of its volume at 0 °C?
Correct answer B. 1/273