Question

Homework Thermochemistry Name: 1. Calculate the mass of O2 that is produced by photosynthesis when 2.49 x 10° kJ of solar energy is consumed by the following reaction: 6 H20 (1) + 6 CO2 (g) C6H12O6 (s) + 6 O2 (g) ; AH = 2803 kJ 2. Given the following thermochemical equation, what amount of energy is absorbed/given off when 255 g of Cu20 is reacted. 2 Cu20 (s) 4 Cu (s) + O2(g) ; AH = 333.8 kJ 3. Is the reaction in question (2) exothermic or endothermic? 4. Classify each of the following processes as exothermic or endothermic a) ice melting b) a sparkler burning c) acetone evaporating from skin

Answer 1

ACTZON 2- PHOTOSYNTHESIS 64,016) + 6(QCy) - In 64,20,4) +64G, 44=2803KJ. so, 6 moles of produced by the consumption of 2802 KT of solar energy in photosynthesis. 8803 KJ of solar energy is consumed by 6 moles of a so 2.49 X107 kJ of solar energy is consumed by {X2.49 X10" moles off - 2 53.3 moles of a No. of moles = goren may - Molar mass = 53.3 X 32 g of a - 2 170506g of Q. No. of Moles & Molar man ? given mari Molar mass of 2 = 2 X 16 g/mole = 32g/mole 9 co - 4 Cu q9), AH = 333. PKT. absorbed 2 moles of huo / gives off 33308 KJ of energy 2 х/ч 3 1 14. • /2 4 333. Клу елеу. so assy of caz o f gives off 337.8 x 15 kg of energy I Molar mass of ' 0 = 143 g/mole) borb = 297062 67 of energy 13. since the above reaction is a decomposition amporonion reaction reaction a and for that

energy has to be adsorbed so It is an endothermic reaction. (4) Ice Melting - laj Endothermie process as heat is required to Convert solid into liquid. (water). Cice) (6) A sparkler burning - Burning of sparkler is an exothermic process as it gives off a lot of energy as it ū a Cembustion reactien, . (C) Acetone evaporating from alleen in acelera Atet Acetine evaporates in air by utilising the heat from skin causing the skin a wiling effect to ith a Endothermic process.