percent Yield

Notes from Transcript

Page 1: Key Concepts in Chemistry

Percent Yield

• Definition: A measure of the efficiency of a reaction.

  • Formula:

    • Percent Yield = (Actual Yield / Theoretical Yield) x 100

  • Example Values:

    • Actual Yield: 14.7

    • Theoretical Yield: 100,000 Pa (1.01325 atm)

Atmospheric Pressure

• Conversions:

  • 1 atm = 760 torr = 760 mm Hg

  • 1 mmHg = 1 torr

Thermodynamics

• Entropy: A measure of disorder in a system.

• Heat Calculations:

  • Formula: ( P V = n R T )

    • Where:

      • P = Pressure

      • V = Volume

      • n = Moles

      • R = Ideal gas constant (0.0821 atm·L/(mol·K))

      • T = Temperature

Molar Calculations

• Moles to Grams:

  • Use molar mass to convert between grams and moles.

• Heat Transfer:

  • Heat (kJ) = moles x molar heat capacity

Freezing Point Depression

• Formula:

  • ( \Delta T_f = i \cdot K_f \cdot m )

    • Where:

      • ( \Delta T_f ) = change in freezing point

      • ( i ) = van 't Hoff factor

      • ( K_f ) = freezing point depression constant

      • ( m ) = molality (moles of solute per kg of solvent)

Boiling Point Elevation

• Formula:

  • ( \Delta T_b = i \cdot K_b \cdot m )

    • Where:

      • ( \Delta T_b ) = change in boiling point

      • ( K_b ) = boiling point elevation constant

Concentration Calculations

• Mass Percent:

  • % m/m = (Mass of Solute / Mass of Solution) x 100

• Parts Per Million (ppm):

  • ppm = (Mass of Solute / Mass of Solution) x 1,000,000

• Parts Per Billion (ppb):

  • ppb = (Mass of Solute / Mass of Solution) x 1,000,000,000

Molarity

• Definition: Concentration of a solution expressed as moles of solute per liter of solution.

  • Formula:

    • M = moles of solute / liters of solution

Dilution

• Dilution Formula:

  • ( C_1 V_1 = C_2 V_2 )

    • Where:

      • ( C_1 ) = initial concentration

      • ( V_1 ) = initial volume

      • ( C_2 ) = final concentration

      • ( V_2 ) = final volume

Additional Notes

• Ensure units are consistent when performing calculations.

• Familiarize with the formula sheet for quick reference during problem-solving.