Definitions and MCQs of Ninth Class Chemistry (chemical energetics)
Chapter 10Chemical Energetics(The failure is the result of disobedience offirst parents then teachers and finally ofthe Almighty Allah)
Definitions1. Thermodynamics: -The study of conversionand conservation of heat and other forms ofenergy is called thermodynamics.2. Thermochemistry: - it deals with themeasurement or calculation of heat absorbed orabandoned in chemical reactions.3. Thermo chemical reactions: - the chemicalreactions which are accompanied by energychanges along with the material changes aregenerally known as thermochemical reactions.4. Exothermic reactions: -the chemical reactionswhich are accompanied by the liberations oremission of energy are called exothermicreactions.5. Endothermic reactions: -the chemicalreactions which are accompanied by theabsorption of energy are called endothermicreactions.6. system: -the collection of matter having certainboundaries is called system7. Surroundings:- the environment of a system orthe thing that affect on a system are included insurroundings.
8. Heat of formation: - the change of enthalpywhen one gram mole of a substance is formedfrom its elements9. Standard heat of formation: -the change ofenthalpy when one gram mole of a substance isformed from its elements at 25oC and 1 atm iscalled standard heat of formation.10. Enthalpy: -the total heat content of a system iscalled enthalpy..11. Heat of neutralization: - The amount of heatreleased during the neutralization process whenone mole of water is produced by the reaction ofacid and base.
Multiple Choice Questions1. Thermochemical reactions involve:a) material changes b) energy changesc) both a & b d) heat changes2. EXO means:a) out of or to evolve b) into or to absorbc) outside d) heat3. ∆H negative represents which reaction:a) thermochemical b) exothermicc) endothermic d) chemical4. Formation of water from hydrogen and oxygenproduces energy:a) -286 K.J/mole b) +286 K.J/molec) -393 K.J/mole d) +393 K.J/mole5. ∆H positive represents neutralization:a) true b) false6. Acid Base reaction is called neutralizationreaction:a) true b) false Questions 7 – 12• Select from the terms below:A) endothermic reaction B)exothermic reaction7. photosynthesis
8. respiration9. decomposition reaction10. bond formation11. combustion12. melting of iceThe Book MCQs13. in an exothermic reaction:a) heat energy is lost b) heat energy is gainedc) both a & b d) N.O.T14. In an exothermic reaction:a) container becomes hotb) container becomes coldc) the temperature of container remains samed) N.O.T15. During an endothermic reaction:a) container becomes coldb) container becomes hotc) the temperature of container remains samed) N.O.T1 C 2 A 3 B4 A 5 B 6 A7 A 8 B 9 A10 B 11 B 12 A13 A 14 A 15 A