Question

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1. How do we know when a chemical reaction is taking place? Can you think of an example of how each of the five senses (sight, hearing, taste, touch, smell) All even-numbered Questions and Problems have ans

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Answer 1

Chemical reaction occurs by chemical change. Changes in which atoms rearrange themselves by combining! exchange or break apart are called chermical reactions. But we cannot bee atom undergoing the change. so, we must see the physical aspect in order to check! whether a chemical reaction has occured like! colour change. A changes offen occurs in a channel reaction, PbS Halo Pbson black white " Temperature changes! Heat can be released or absorbed in a chemical ! reaction. as Endothermc x When heat is absorbed in a Chemical syne x endothermic son occurs. containei in which son takes place becomes cool. el Balth & 2N Hy is that Ball +2Nhuah 6) Exotherme sant when heat is released in a chemical sxn, exothermic son occuro. Contained in which sah occure becomes hot I 2Mg et Or r ego & heat Precipitate Formation! precipitate is an insoluble solid that emerges from a liqued solution 9. Balla & Hasan Basoud & 244 white preuptate light emission: many reaction occure by guing off night Pt2 - P400 & blame in) V

w Gas production! Some produce gas as a eg zu & H₂SO4 chernical reactions product zusoy & the on gas.