I have an unknown initial volume of gas held at a temperature of 115 K in a
container with a pressure of 6 atm. I
increase the temperature to 225 K and
decrease the pressure to 2,800 mmHg
and it causes the final volume of the gas
to be 29 L. What was the initial
volume?

V₁ = 0.025 Liters = 25 ml

Explanation:

P₁ = 6 Atm      P₂ = 7800mm/760mm/Atm = 0.01 Atm

V₁ = ?              V₂ = 29 Liters

T₁ = 115 K        T₂ = 225 K

P₁V₁/T₁ = P₂V₂/T₂ => V₁ = P₂V₂T₁/P₁T₂

V₁ = (0.01 Atm)(29L)(115K)/(6 Atm)(225K) = 0.025 Liters = 25ml

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

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.