Nazhpo4.7h2o is to be produced in an evaporative crystallizer by cooling an aqueous solution of nazhpo4 to 305 k which saturates at 315 k. cooling water enters and leaves the unit at 285 k and 290 k respectively. it is required to produce 500 kg/hr of product through the process. the solubility of anhydrous na2hpo4 in water is 32 kg/100 kg water at 315 k and 22 kg/100 kg water at 305 k additional information: a. the available heat transfer area is 2,5 m2 1 m lengths b. a single section of the crystallizer is 0.8 m long c. the heat of crystallization is 220 kj/kg d. the mean heat capacity of the solution is 3.6 kj/kg e. the overall heat transfer coefficient (u) is 0.16 kw/m2k f. 0% of the water entering the crystallizer is evaporated 1.1. draw a schematic diagram that depicts the crystallization process showing all the entering and leaving streams with the given information. 1.2. determine the number of sections of crystallizer that will be required to produce the product

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

it's c. elements are placed in rows based on how may valencies electrons have.