Predators are the consumers
Unfortunately the data provided doesn't include the DENSITY of the ammonium chloride solution and molarity is defined as moles per volume. So without the density, the calculation of the molarity is impossible. But fortunately, there are tables available that do provide the required density and for a 20% solution by weight, the density of the solution is 1.057 g/ml.
So 1 liter of solution will mass 1057 grams and the mass of ammonium chloride will be 0.2 * 1057 g = 211.4 g. The number of moles will then be 211.4 g / 53.5 g/mol = 3.951401869 mol. Rounding to 3 significant digits gives a molarity of 3.95.
Now assuming that your teacher wants you to assume that the solution masses 1.00 g/ml, then the mass of ammonium chloride will only be 200g, and that is only (200/53.5) = 3.74 moles.
So in conclusion, the expected answer is 3.74 M, although the correct answer using missing information is 3.95 M.
Answer:
(iii) A has pH greater than 7 and B has pH less than 7
Explanation:
Phenolphthalein is a common indicator in acid base titrations. It turns pink in basic conditions and turns colorless in acidic conditions. Thus on addition of solution A it becomes pink so A should be basic having pH more than 7. On addition of B , it turn out to be colorless means that B is an acidic solution having pH less than 7.
