Chemistry 1.25: Unit 6 Wrap-Up

Multiple Choice

Kinetic Theory states that atoms and molecules are constantly in:

• motion

• phases

• reaction

• trouble

• state

Multiple Choice

What phase will $$CO_2$$  be in at 15 atm and $$-40\degree C$$  

• Solid

• Liquid

• Gas

Multiple Choice

The presence of which type of intermolecular forces in a liquid will lead to the highest boiling point?

• Van der Waals

• Dipole-dipole forces

• Hydrogen bonding

Multiple Choice

Which type of solid has the weakest forces holding it together?

• Molecular

• Metallic

• Network

• Ionic

Multiple Choice

When a solute such as salt is added to a solvent such as water, the temperature at which the solution freezes becomes:

• Lower

• Higher

• There is no change

Multiple Choice

Which of these compares moles of solute to the mass of a solvent?

• Molality

• Molarity

Multiple Choice

Salt (NaCl) is added to water. What is the freezing point of the solution if the molality is 2.25 mol/kg?

Kf = 1.86

i = 2

• $$-16.74\degree C$$  

• $$-8.37\degree C$$  

• $$0\degree C$$  

• $$8.37\degree C$$  

Multiple Choice

Which is the correct $$K_{eq}$$  for this reaction:

$$2NO\left(g\right)\ +\ 2H_2\left(g\right)\ \leftrightarrow\ N_2\left(g\right)\ +\ 2H_2O\left(g\right)$$  

• $$K_{eq}\ =\ \frac{\left[N_2\right]\left[H_2O\right]}{\left[NO\right]^2\left[H_2\right]}$$  

• $$K_{eq}\ =\ \frac{\left[N_2\right]\left[H_2O\right]^2}{\left[NO\right]^2\left[H_2\right]^2}$$  

• $$K_{eq}\ =\ \frac{\left[NO\right]^2\left[H_2\right]}{\left[N_2\right]^2\left[H_2O\right]}$$  

Multiple Choice

Use the equation and the concentrations given to calculate $$K_{eq}$$  :

$$K_{eq}\ =\ \frac{\left[N_2\right]\left[H_2O\right]^2}{\left[NO\right]^2\left[H_2\right]^2}$$  

$$\left[NO\right]\ =\ 2\ M$$  

$$\left[H_2\right]\ =\ 2\ M$$  

$$\left[N_2\right]\ =\ 1.5\ M$$  

$$\left[H_2O\right]\ =\ 3\ M$$  

• 0.40

• 0.84

• 1.12

• 1.18

Multiple Choice

If $$K_{eq}\ =\ 0.84$$  are there more products or reactants present at equilibrium?

• Products

• Reactants

Multiple Choice

$$H_2\left(g\right)\ +\ I_2\left(g\right)\ \leftrightarrow\ 2HI\left(g\right)$$  

This system is at dynamic equilibrium. What happens if you increase the concentration of HI(g)?

• The equilibrium position will shift to the reactant side.

• The equilibrium position will shift to the product side.

• There will be no change.

Multiple Choice

$$CaCO_3\left(s\right)\ \leftrightarrow\ CaO\left(s\right)\ +\ CO_2\left(g\right)$$  

This system is at dynamic equilibrium. What happens when you remove some of the CaO from the reaction chamber?

• The equilibrium position will shift to the reactant side.

• The equilibrium position will shift to the product side.

• There will be no change.

Multiple Choice

What is meant by the rate of reaction?

• How far to completion the reaction goes

• How much energy the reaction requires

• How concentrated the final products are

• How slow or fast a reaction progresses

Multiple Choice

What does the "hill" represent in an energy diagram?

• The energy of the reactants

• The energy of the products

• The activation energy

• Total energy of the system

Multiple Choice

What would decrease the rate of the formation of ammonia $$\left(NH_3\right)$$  ?

$$N_2\left(g\right)\ +\ 3H_2\left(g\right)\ \leftrightarrow\ 2NH_3\ \left(g\right)\ +\ heat$$  

• Increasing the temperature

• Increasing the pressure

• Increasing the concentration of reactants

• Decreasing the temperature

Multiple Choice

What effect would a catalyst have on the reaction?

• It shifts equilibrium to the left.

• It decreases the activation energy.

• It decreases the reaction rate.

• It increases the concentration of the reactants.