1 / 7

Energy & Stoichiometry

Energy & Stoichiometry. Exothermic and Endothermic. HEAT. HEAT. Exothermic process – heat is released into the surroundings Exo = Exit Endothermic Process – heat is absorbed from the surroundings Endo = Into. Thermochemical Equations.

yeva
Download Presentation

Energy & Stoichiometry

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. Energy &Stoichiometry

  2. Exothermic and Endothermic HEAT HEAT • Exothermic process – heat is released into the surroundings • Exo = Exit • Endothermic Process – heat is absorbed from the surroundings • Endo = Into

  3. Thermochemical Equations • In a thermochemical equation, the energy of change for the reaction can be written as either a reactant or a product • Enthalpy: the heat content of a system at constant pressure (ΔH) • Endothermic (positive ΔH) 2NaHCO3 + 129kJ Na2CO3 + H2O + CO2 • Exothermic (negative ΔH) CaO + H2O Ca(OH)2 + 65.2kJ

  4. Exo 4 3 2 1 mol 10.00g Fe 1652 kJ =73.97 kJ of heat 4 mol Fe 55.85g Fe Write the thermochemical equation for the oxidation of Iron (III) if its ΔH= -1652 kJ Fe(s) + O2(g)→ Fe2O3(s) + 1652 kJ How much heat is evolved when 10.00g of Iron is reacted with excess oxygen?

  5. Endo 1 mol NaHCO3 50.0 g NaHCO3 129kJ 83.9 g NaHCO3 2mol NaHCO3 =38.4kJ of heat Write the thermochemical equation for the decomposition of sodium bicarbonate, with a ΔH = + 129 kJ: 2 NaHCO3 + 129kJ → Na2CO3(s) + H2O + CO2 How much heat is required to break down 50.0g of sodium bicarbonate?

  6. Exo 100 g CaO 1 mol CaO 65.2kJ 56.07 g CaO 1mol CaO =116kJ of heat Write the thermochemical equation for a single replacement of calcium oxide and water with a ΔH= - 65.2 kJ: CaO + H2O → Ca(OH)2 + 65.2kJ How much energy is released when 100 g of calcium oxide reacts?

  7. Endo 420kJ 1 mol O2 31.98 g O2 =218 gof O2 61.5 kJ 1mol O2 Write the thermochemical equation for the decomposition of magnesium oxide with a ΔH= + 61.5 kJ: 2MgO + 61.5 →2 Mg + O2 How many grams of oxygen are produced when magnesium oxide is decomposed by adding 420 kJ of Energy?

More Related