Planning_Question_from_other_schools

1 Planning Question from other schools 1 Concept: Precipitation reaction to precipitate out all the silver ions. Hence, excess aqueous NaCl need to be used. AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) Ag+(aq) + Cl- (aq) → AgCl(s) Mole ratio of AgCl : Ag+ = 1:1

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4 4 5 Concept: Use 20 cm3 of 30% (w/v) H2O2 and dilute with 80 cm3 with distilled water. M1V1 = M2V2 300 𝑀𝑟 x 20 = 60 𝑀𝑟 x V V = 100 cm3 (total volume of solution is 100 cm3) Using a 50 cm3 measuring cylinder, measure 20 cm3 of 30% (w/v) H2O2 into a beaker. Using another measuring cylinder, measure 80 cm3 of distilled water and pour it into the beaker and swirl to obtain 100 cm3 of 6 % (w/v) H2O2.

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