helpFirst, each antacid tablet is mixed with 40 mL of 0.1 M HCl this acidic solution is the same stuff that...

ok, here we go.

firstly, you have to work out the number of moles in the 40 mL of HCl, which is n = cv (concentration*volume in dm^3)

40mL is 0.04 dm^3 (as one dm^3 is 1 Litre), therefore, the number of moles of HCl = 0.04*0.1 = 0.004 mol.

then you have to work out how many moles the NaOH neutralised. 1 mole of NaOh neutralises 1 mole of HCl, deduced from the equation NaOH + HCl -> NaCL + H20.

therefore we know that 40mL of NaOH of 0.1M concentration neutralises the 40 mL of 0.1 M HCl. this allows us to work out the number of moles of NaOH used to neutralise the acid left after the antacid tablets. this works out the number of moles of acid actually left. nunmber of moles=concentration * volume in dm^3

which =

for Maalox, 0.0241 L*0.1M= 0.00241 moles used to neutralise excess acid.

for Tums, 0.0224*0.01= 0.00224

for Mylanta, 0.0200*0.1 = 0.00200

for CVS, 0.0199*0.1 = 0.00199

for Rennies, 0.0244*0.1= 0.00244

1)so we can see that CVS used the least amount of NaOH to neutralise the excess acid, therefore it is the strongest antacid per single dose.

then for 2), we need to find out how many moles of acid are left per gram of antacid.

to do this we divide all the previous values above by the weights of the antacid doses

for Maalox, 0.00241/20.0 = 0.0001205

for Tums, 0.00224/21.0 = 0.0001143

for Mylanta, 0.002/18 = 0.0001111

for CVS, 0.00199/18.3 = 0.0001087

for Rennies, 0.00244/17.5= 0.0001394

so, we see that CVS is the strongest antacid per gram, because it did not react with the least amount of moles of acid per gram of antacid (what a mouthful!!).

for 3) the most apparent colour change in neutralistion reactions is to use phenolpthalein indicator (what a mouthful again!!) because it turns bright pink in acid, and colourless in alkali.

Put 'em in a nice pretty case that plays "Waltz of the the Flowers" from the Nutcracker as they turn on a rotating shelf...... Oh... and it would help if they were color coordinated and stood upright...... A pretty little Tums™ ballet!

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