Physical Sciences P2 - Multiple Choice

Solubility of NaCl in Water

• NaCl has a high solubility in water due to the polar nature of water molecules, allowing them to interact effectively with the ionic nature of NaCl.
• The correct explanation for NaCl's solubility is that the electrostatic forces between ions in NaCl are comparable to the intermolecular forces present in water.

Bond Length Factors

• Bond length between two atoms is influenced by several factors, including:
  • The size of the atoms, as larger atoms generally form longer bonds.
  • The number of bonds between the atoms, where multiple bonds are shorter.
• The difference in electronegativity and valencies of the atoms does not directly affect bond length.

Insect Mobility on Water

• Surface tension is the phenomenon that enables insects like mosquitoes to walk on water.
• This is caused by the cohesive forces between water molecules, creating a "skin" on the surface.

Kinetic Molecular Theory of Gases

• Kinetic Molecular Theory emphasizes:
  • Gas molecules are in constant and random motion.
  • Collisions between gas molecules are elastic, meaning energy is conserved during collisions.
• A misconception within the theory is that not all molecules possess the same kinetic energy, making that statement incorrect.
• Attractive and repulsive forces between gas molecules can indeed be neglected in ideal gas behavior.