Atank of methane gas contains 2.8 m³ of the gas at 20°c. the tank has a pressure-release valve that releases gas into a secondary tank that will hold 0? 2m³ of gas if the pressure rises. at what celsius temperature will the methane fill both tanks?
*using boyles law, charles law, or gay lussacs law

There is a typo in the question. hopefully, i assumed the correct number.

when volume and temperature are given, that means you need Charles' law. remember that with any gas formula, the temperature has to be in Kelvin which can be determined by simply adding 273 to Celsius.

Charles' law---> V1/T1 = V2/T2

V1= 2.8 m3
T1= 20 C = 293 K
V2= 0.2 m3
T2=

let's plug in the values

2.8/ 293 = 0.2/ T2

T2= 20.9 Kelvin

to change the answer to Celsius, just subtract 273 to the temperature

20.9 - 273= -252 Celsius

30litre of li2o is 1.0002mole approximately 1 mole