A sample of carbon dioxide occupies 10.0 L under STP conditions. At what pressure wouldcthis same sample have a volume of 12.5 L and a temperature of 20.0oC?

0.859 atm

Explanation:

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

where,

= initial pressure of gas (STP) = 1 atm

= final pressure of gas = ?

= initial volume of gas  (STP) = 10.0 L

= final volume of gas = 12.5 L

= initial temperature of gas (STP)  = 273K

= final temperature of gas =

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

Thus at 0.859 atm , same sample have a volume of 12.5 L and a temperature of

since electrons are negative the answer is neagtaive