Molar Enthalpies and Calorimetry Lesson Outline Crash Course

  • Slides: 12
Download presentation
Molar Enthalpies and Calorimetry

Molar Enthalpies and Calorimetry

Lesson Outline • Crash Course on Enthalpy • Enthalpy of Reaction and Molar Enthalpy

Lesson Outline • Crash Course on Enthalpy • Enthalpy of Reaction and Molar Enthalpy of a Reaction • Calculating Molar Enthalpy of a Reaction using Calorimetry

Learning Expectations • Use specific values to calculate the molar enthalpy and the enthalpy

Learning Expectations • Use specific values to calculate the molar enthalpy and the enthalpy of reaction.

Crash Course on Enthalpy https: //www. youtube. com/watch? v=SV 7 U 4 y. AXL

Crash Course on Enthalpy https: //www. youtube. com/watch? v=SV 7 U 4 y. AXL 5 I&t=24 s

Enthalpy of Reaction and Molar Enthalpy of a Reaction Enthalpy of Reaction (k. J):

Enthalpy of Reaction and Molar Enthalpy of a Reaction Enthalpy of Reaction (k. J): refers to the energy change for a whole chemical system with reactants change to products Molar Enthalpy of Reaction (k. J/mol): is the energy change in a chemical system per mol of a specific chemical

Predict the change in enthalpy due to the combustion of 10. 0 g of

Predict the change in enthalpy due to the combustion of 10. 0 g of propane used in a camp stove Δc. H = nΔc. Hm = -2043. 9 k. J/mol

Predict the enthalpy change due to the combustion of 10. 0 g of butane

Predict the enthalpy change due to the combustion of 10. 0 g of butane in a camp heater. The molar enthalpy of combustion of butane to produce water vapour is 2657. 3 Kj/mol.

Molar Enthalpy using Calorimetry The combustion of 3. 50 g Ethanol in a calorimeter

Molar Enthalpy using Calorimetry The combustion of 3. 50 g Ethanol in a calorimeter causes a temperature of 3. 63 L of water to increase from 19. 88 ‘C to 26. 18 ‘C. Use this information to determine the molar enthalpy of combustion of ethanol.

If ΔH = Q Then… nΔc. Hm =

If ΔH = Q Then… nΔc. Hm =

1. What is the significance of a positive or negative sign for enthalpy change?

1. What is the significance of a positive or negative sign for enthalpy change? 2. Predict the enthalpy change for the combustion of 100 g of methane in a natural gas water heater. (Δc. Hm (CH 4) = -802 ckj/mol). 3. In a calorimeter, 2. 98 g of methanol was burned to raise the temperature of 650 g of water by 20. 9 ‘C. Calculate the molar enthalpy of combustion of methanol.

Success Criteria

Success Criteria