What is the percentage of water in hydrated calcium chloride

24.5%

Explanation:

You just add up the atomic masses.  

Ca - 40.078  

Cl2 - 35.4527 x 2 = 70.9054  

110.9834  

H4 - 1.00794 x 4 = 4.03176  

O2 - 31.9998  

36.03056  

TOTAL - 147.01396  

So the water is 36.03056/147.01396 = .245082576 but that is only accurate to three decimals (because the mass of Ca was only given to three decimals) so we write .245 and that is 24.5%

This is not my answer but I found it on Yahoo answers and it was answered by Anonymous.

24.5%

Explanation: Molar mass of CaCl2 * 2 H2O = 40.078 + ( 2 x 35.453) + ( 2 x 18.02)=147.024 g/mol  

% H2O = 2 x 18.02 x 100/ 147.024 =24.5

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.

if you mean hydrogen and oxygen then water is the product