Question 161607
The volume V of an ideal gas varies directly with the temperature T & inversely
 with the pressure P. Write an equation relating V,T, and P using k as the
 constant of proportionality. If a cylinder contains oxygen at a temperature of
 300 K and a pressure of 15 atmospheres in a volume of 100 liters, what is the
 constant of proportionality k?
The equation for this:
V = {{{(Tk)/P}}}
Where:
V = 100
T = 300
P = 15
:
{{{(300k)/15}}} = 100
Multiply both sides by 15, results:
300k = 15(100)
k = {{{1500/300}}}
k = 5
:
V = {{{(5T)/P}}} is the formula 
:
:
If a piston is lowered into the cylinder, decreasing the volume occupied by
 the gas to 80 liters and raising the temperature to 310 K, what is the gas
 pressure
:
In the above equation:
V = 80
T = 310
find P
:
80 = {{{(5*310)/P}}}
Multiply both sides by P
80P = 1550
P = {{{1550/80}}}
P = 19.375 atmospheres