Asample of manganese (ii) chloride has a mass of 19.8 grams before heating, and 12.6 grams after heating until all the water is driven out. based on this information, how many water molecules were attached to each molecule of manganese (ii) chloride

no. of water molecules associated to each molecule of = 4

Explanation:

Mass of before heating = 19.8 g

Mass of after heating = 12.6 g

Difference in mass of before and after heating

                                 = 19.8 - 12.6 = 7.2 g

Difference in mass corresponds to mass of water driven out.

Molar mass of water = 18 g/mol

No. of moles of water =

Mass of obtained after heating is mass of anhydrous .

Mass of anhydrous = 12.6 g

Molar mass of = 125.9 g/mol

No. of mol of anhydrous =

so,

0.1 mol of have 0.4 mol of water

1 mol of will have =

Hence, no. of water molecules associated to each molecule of = 4

here we have to get the change of moles on decrease the volume of the reaction in gas phase.

the   per the given options it will decrease by (d) 11-50%

we know, on decreasing the volume of the gas phase reaction the reaction moves to the product side.

the reaction:                     so₂cl₂ (g) = so₂ (g) + cl₂ (g)         total

the moles at equilibrium:   1 - α                 α               α           = 1+α

concentrations:                   1 - α               α               α           = 1 + α

(concentration = moles/volume, as volume is 1 l)

(where α is the degree of dissociation)

now the dissociation constant in terms of concentration is :

=  

or,

or,   = (at v = 1l)

the reaction:                     so₂cl₂ (g) = so₂ (g) + cl₂ (g)         total

the moles at equilibrium:   1 - α                 α               α           = 1+α

concentrations:               (1 - α)/0.5           α/0.5         α/0.5       = (1 + α)/0.5

thus, the dissociation constant in terms of concentration is :

or,  

=  

so, the change of 1 : 1/0.5

or, 1: 2

thus it will decrease by 50%.

or, as per the given options it will decrease by 11-50%

i'm wiling to try and you : )