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aboratory Assignment ts of the 3. A student performed an experiment similar to t

ID: 1049220 • Letter: A

Question

aboratory Assignment ts of the 3. A student performed an experiment similar to the ware f one that you will perform but used different solutions. ly comThe student's data are presented in the table below. of: Student data for estimating the pH of solutions indicator color 0.1M Thymol Methyl Bromothymol Blue Blue solution NaNO3 red NaNO2 green HNO3 red HNO2 orange red Red yellow blue yellow red yellow (1) Is a 0.1M NaNO2 solution acidic or basic? What experimental evidence supports your STAR answer? ne the owing halein (2) List the acidic solution(s) studied by the student. llow R What experimental evidence supports your aining answer?

Explanation / Answer

answer 1 ) well when we test our 0.1 M NANO2 solution with

1) methyl red ( below 4.4 pH= red ) ( above pH= 6.2 yellow )

2) bromothymol blue ( below pH= 6   yellow ) ( above pH = 7.6 blue )

hence we get yellow with methyl red and blue with bromothymol blue we can say the pH must be grater or equal to = 7.6 hence it must be basic as pH > 7 .

answer 2) the   acidic solution are those which show yellow to bromothymol blue .

NaNO3 , HNO3 ,HNO2

as when pH is less then 6 it shows yellow colour and for those it shows blue it means they must have greater ph > 7.6 .

answer 3) the incresing order of acidity

NaNO2 <NANO3<HNO2 <HNO3

as methyl red shows red colour to only HNO2 and HNO3 that means they have pH<4.4 and thymol blue shows red colour only to HNO3 it means it has pH<1.2 . and is most acidic

hence NANO3 is lesser acidic than above two

we already explain the basic nature of NANO2