Kp

• What is the definition of partial pressure?

  Pressure a gas would have alone in volume
• How is total pressure calculated in a mixture of gases?

  Total pressure equals the sum of partial pressures
• What is the formula for total pressure in a mixture of three gases?

  P = p1 + p2 + p3
• How is the partial pressure of a gas calculated?

  Partial pressure = mole fraction x total pressure
• What is the formula for mole fraction?

  Mole fraction = number of moles of gas / total moles
• What does Kp represent?

  Kp is the equilibrium constant for gases
• What should be ignored in the Kp expression?

  Ignore solids, liquids, and aqueous substances
• What happens to Kp if the reaction is reversed?

  Kp becomes the inverse of the original
• How does Kp relate to the amount of products in a reaction?

  Larger Kp indicates greater amount of products
• What factors do not change Kp?

  Pressure, concentration, and catalysts do not change Kp
• How does temperature affect Kp?

  Kp changes if temperature is altered
• What happens to the equilibrium position if temperature is increased in an exothermic reaction?

  Equilibrium shifts left, Kp decreases
• What happens to Kp when pressure is increased?

  Kp remains constant despite pressure increase
• How does the equilibrium position shift with increased pressure in a reaction with fewer moles of gas on the product side?

  Equilibrium shifts right towards products
• What does the variable P represent in the Kp expression?

  P represents total pressure in Kp expression
• What are the steps to calculate Kp from a reaction at equilibrium?

  1. Determine initial moles of reactants and products.
  2. Calculate moles reacted and formed at equilibrium.
  3. Find mole fractions of each gas.
  4. Calculate partial pressures using mole fractions and total pressure.
  5. Substitute into Kp expression.
• What are the effects of changing temperature and pressure on Kp?

  • Temperature changes Kp value.
  • Pressure changes equilibrium position but not Kp.
  • Increased pressure shifts equilibrium towards fewer moles of gas.