IMF and Thermo - Most Missed F23

What units are used to measure heat?

• J/mol or kJ/mol

• Kelvin or Celsius

• Joules or kilojoules

• none of the above

Which of the following is true regarding the origin of dipole forces between molecules?

• It comes from strong charges in molecules due to highly polar bonds between hydrogen and oxygen, hydrogen and fluorine, or hydrogen and nitrogen.

• They result from the interactions between positive and negative ions.

• They result from the attraction of temporary regions of positive and negative charges that arise in molecules.

  
  

• They result from the attraction of the positive and negative ends of separate polar molecules.

Which of the following describes heat?

• the energy transferred between samples of matter because of a difference in their temperatures

• a measure of the average kinetic energy of the particles in a sample of matter

• the energy stored in a sample of matter

• bond energy

What is the main IMF found in the CO?

• Ion-dipole

• Hydrogen bonding

• Dipole-Dipole

• London Dispersion

What type of intermolecular force is the result of temporary uneven distribution of electrons around molecules that result in momentary dipoles?

• dipole-dipole

• london dispersion

• london dispersion and dipole-dipole

• hydrogen bonding

Which of the following accounts for why Br₂ is a nonpolar molecule with a boiling point of 59^oC, while HF is a polar molecule with a boiling point of 19.5^oC?

• The London dispersion forces in Br₂ are weaker than the London dispersion forces in HF.

• The London dispersion forces in Br₂ are weaker than the hydrogen bonds in HF.

• The London dispersion forces in Br₂ are weaker than the dipole-dipole forces in HF.

• The hydrogen bonds in HF are weaker than the London dispersion forces in Br₂.

For a given substance, which of the following phase changes should release the most energy?

• solid to liquid

• solid to gas

• gas to liquid

• liquid to solid

I. Molecules that have the ability to form hydrogen bonds do not have the ability to form any other types intermolecular forces.

BECAUSE

II. Polar molecules such as water are attracted to other polar molecules only by hydrogen bonding.

• Statement I is true, Statement II is true

• Statement I is true, Statement II is false

• Statement I is false, Statement II is true

• Statement I is false, Statement II is false

• Statement I is true, Statement II is true and is a correct explanation of the phenomena described in I

Consumers use many products made of plastic.  Plastics are carbon-based polymers made from smaller carbon compounds called monomers. In organic molecules, the carbon atoms and the hydrogen atoms are held together by ___________.

• hydrogen bonds

• covalent bonds

• ionic bonds

• nuclear bonds

If identical quantities of heat are allowed to flow into 50.0g samples of each of the metals, all at the same initial temperature, which would reach the highest temperature?

• aluminum

• copper

• gold

• silver