Solid potassium chlorate decomposes into solid potassium chloride and oxygen gas. if 2.00 g potassium chlorate decomposes in a chamber with a fixed volume of 0.800 l, and temperature of 25.0◦c. what is the final chamber pressure? assume all the potassium chlorate decomposes. express your answer in atmospheres.

Answer : The final chamber pressure is 0.746 atm.

Explanation:

First we have to calculate the moles of .

Molar mass of = 122.5 g/mole

Now we have to calculate the moles of .

The balanced chemical reaction will be:

From the balanced reaction we conclude that,

As, 2 moles of react to give 3 moles of

So, 0.0163 moles of react to give moles of

Now we have to calculate the pressure of gas.

Using ideal gas equation:

where,

P = pressure of gas = ?

V = volume of gas = 0.800 L

T = temperature of gas =

R = gas constant = 0.0821 L.atm/mole.K

n = number of moles of gas = 0.0244 mole

Now put all the given values in the ideal gas equation, we get:

Therefore, the final chamber pressure is 0.746 atm.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml