Ahydrate of copper (ii) chloride has the following formula: cucl2 - x h2o. the water in a 3.41-g sample of the hydrate was driven off by heating. the remaining sample had a mass of 2.69 g . find the number of waters of hydration (x) in the hydrate.

x=2 (

Explanation:

Mass of is the mass of remaining sample, because it is a product of loss of drying from initial sample. This means that the mass of water is the mass has been lost.

after fing the masses of and water you must to find the amount of moles in both cases.

Now you must to find the ratio between both molecules:

So the water is two times copper(II) chloride. (

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2