If you mass 0.430 g of Co(NO3)2 6H2O and dissolve it in water, what further information would you need to calculate:. a. the number of moles of Co(NO3)2 in the solution?
b. the molarity of the solution

a. No information is required.

b. The volume of the solution.

Explanation:

Hello!

In this case, since hydrates are salts which have additional water in their structures, when making mole-mass calculations involving them, we need to consider the how many water molecules we find in the hydrate. In such a way, for 0.430 g of cobalt nitrate hexahydrate (six water molecules), we proceed as follows:

a. Since we have 0.430 g of hydrate, we may compute the moles of anhydrous cobalt nitrate by using the molar mass of the hydrate (291.04 g/mol) and then, by noticing that one mole hydrate has one mole of anhydrous, we are able to compute the moles of anhydrous cobalt nitrate as shown below:

It means no further information is required.

b. Since the molarity is defined by the division of the moles of solute over liters of solution (M=mol/V), we would need the volume of the solution to successfully compute it.

Bes regards!

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

answerambulatory;