Chemistry Exam Review

These flashcards cover concepts related to lattice enthalpy, ionic compounds, gas laws, and acid-base equilibria to prepare for the chemistry exam.

Which salt has the greater lattice enthalpy, Lithium chloride or Sodium chloride?

Lithium chloride has the greater lattice enthalpy due to its smaller ionic size, resulting in stronger Coulombic attraction.

What happens to the ionic bonds when a salt dissolves in water?

The ionic bonds must break, which is an endothermic process.

What must occur for a dissolving process to be exothermic?

The attraction between the ions and water, forming ion-dipole interactions, must release more energy than was required to break the ionic bonds.

How does an increase in temperature affect the motion of CO2 molecules?

Increasing temperature increases the energy of CO2 molecules, resulting in higher energy collisions and increased pressure.

Explain why the actual pressure of CO2 is less than the predicted pressure according to the ideal gas law.

This is due to intermolecular attractions between CO2 molecules, which makes them behave non-ideally.

What is the action of a strong acid like HBr in water?

A strong acid like HBr dissociates completely into its ions in solution.

In an ionic reaction, what do you not break up?

You do not break up gases, solids, or liquids in solution; only aqueous species are broken up.

What does it signify if a reactant is in excess during a chemical reaction?

It indicates that there is more of that reactant present than is needed to completely react with the limiting reactant.

When measuring pressure in a lab experiment, what is the total pressure after calculating with vapor pressure?

The pressure of the gas is found by subtracting the vapor pressure of water from the total pressure.

What is the importance of understanding ion-dipole interactions in a solution?

Ion-dipole interactions are crucial for explaining the energetics of dissolving ionic compounds in polar solvents.

What type of intermolecular forces are present in covalent networks?

Covalent networks are held together by covalent bonds, unlike other solid forms that are held together by intermolecular forces.

If a collected gas shows signs of being acidic, what could be inferred from its behavior when dissolved in water?

It likely represents an acidic component, which would release H+ ions into the solution.

How do you determine the concentration of hydroxide ions in a solution?

Measure the pH, subtract from 14 to find pOH, and then calculate concentration from pOH.

What formula do you use to calculate pressure in a gas if the volume remains unchanged during a reaction?

Use the formula P1/T1 = P2/T2 to calculate the new pressure.

When creating a buffer solution, what pKa value should be used?

The pKa value closest to the desired pH for the buffer solution.

What is an ideal gas according to the ideal gas law assumptions?

An ideal gas is a theoretical gas composed of many particles that are in random motion, have no attractions or repulsions, and take up no space.