Chemistry, Third edition

13 · ENERGY CHANGES IN CHEMICAL REACTIONS Standard enthalpy of formation The standard enthalpy of formation of a compound H—f^ ...

STANDARD ENTHALPY OF FORMATION 227 ●If an element exists in more than one allotrope, H^ —frefers to the compound pro- ducing re ...

13 · ENERGY CHANGES IN CHEMICAL REACTIONS Calculation of H — using standard enthalpies of formation On page 222, we used Hess’s ...

You might be wondering why the calculation of H^ —fromH—f^ values by this method works. The answer lies in the definition of s ...

230 13 · ENERGY CHANGES IN CHEMICAL REACTIONS say CH 4 (g) and SO 2 (g), since neither compound contains an element common to bo ...

Nutrition Energy value of food Table 13.3 includes the energy value of common foodstuffs, since these can be thought of as ‘huma ...

13 · ENERGY CHANGES IN CHEMICAL REACTIONS If a person’s body is using only carbohydrates to provide energy, the RER is about 1.0 ...

LATTICE ENTHALPY 233 One commercially useful group of materials which produce heat energy extremely rapidly are explosives. Thes ...

13 · ENERGY CHANGES IN CHEMICAL REACTIONS Lattice enthalpy as a measure of the strength of ionic bonding The lattice enthalpy of ...

the endothermic steps cause the total enthalpy to increase (i.e. to move up the figure), whereas the exothermic steps cause the ...

236 13 · ENERGY CHANGES IN CHEMICAL REACTIONS Lattice enthalpy of magnesium fluoride Calculate the lattice enthalpy of magnesium ...

Bond dissociation enthalpies of polyatomic molecules The standard enthalpy change for the reaction: H–O–H(g) H(g)OH(g) H—^  ...

238 13 · ENERGY CHANGES IN CHEMICAL REACTIONS Use of bond enthalpies: fuels – where does the heat come from? The burning of meth ...

REVISION QUESTIONS 239 mean bond enthalpies have been used in for O–H and C–H bonds. Overall, we pre- dictthat the reaction invo ...

13 · ENERGY CHANGES IN CHEMICAL REACTIONS 13.4.50 cm^3 of 0.050 mol dm^3 Ag(aq) and 50 cm^3 of 0.050 mol dm^3 Cl(aq) were ra ...

Speed of Chemical Reactions Objectives Discusses the factors affecting reaction rate Defines the terms rate constantandorder o ...

242 14 · SPEED OF CHEMICAL REACTIONS where[M] (‘delta bracket M’) is read as ‘change in concentration of M’ and t (‘delta t’) ...

REACTION RATE Experimental measurements of the rate of a chemical reaction In order to measure reaction rates experimentally, we ...

244 14 · SPEED OF CHEMICAL REACTIONS Products Reactants Reaction over Time/s Reaction starts when reactants are mixed Concentrat ...

FACTORS AFFECTING REACTION RATE Why reaction rate falls with time So far we have not explained why reaction rate should begin to ...