1 / 9

Calorimetry

Calorimetry. Calculating Heat. Q can be found experimentally by measuring the heat flow accompanying a reaction This is done by measuring temperature This process is called calorimetry. Specific Heat (c). This is amount of heat required to raise the temperature of 1g of a substance 1 ºC

gusty
Download Presentation

Calorimetry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Calorimetry

  2. Calculating Heat • Q can be found experimentally by measuring the heat flow accompanying a reaction • This is done by measuring temperature • This process is called calorimetry

  3. Specific Heat (c) • This is amount of heat required to raise the temperature of 1g of a substance 1ºC • Specific heat is different for different substances • A lower specific heat means that it takes a small amount of heat to change the substance’s temperature

  4. Calculating the Heat Transfer • Heat transfer can be calculated using Q = (c)(m)(Δt) • The specific heat of iron(III) oxide is .75 J/g ºC. What is the heat required to increase the temperature of a 1.75 g sample from 25ºC to 380ºC?

  5. Enthalpy (ΔH) • ΔH is Q at a constant pressure • ΔH is always the J given off per mole of reactant (J/mol)

  6. Example • When 50 ml of a 1.0 M HCl and 50 ml of a 1.0 M NaOH solution are mixed, the temp in a calorimeter increases from 21.0 ºC to 27.5ºC. The total volume of the end solution is 100 ml, its density is 1.0 g/ml, and its specific heat is 4.18 J/gºC. Find the enthalpy change (heat of reaction)?

  7. Water Chamber Calorimetry • Heat lost by a reaction is gained by a quantity of water in a calorimeter • Heat lost = Heat gained • C(water) = 4.184 J/gºC

  8. Example • In a calorimeter containing 100 g of water at 21ºC, a reaction is carried out in which 3.5 g of NH4NO3 decomposes into N2O and H2O. The temperature raises to 25ºC. Find the heat of reaction.

More Related