Under what pressure will a scientist need to store 0.400 miles of gas if the container has a volume of 200.0 ml and the temperature is kept at 23.0 c?

Hello!

Ok so for this problem we use the ideal gas law of PV=nRT and I take it that the scientist needs to store 0.400 moles of gas and not miles.

So if we have
n=0.400mol
V=0.200L
T= 23degC= 273k+23c=296k
R=ideal gas constant= 0.0821 L*atm/mol*k

So now we rearrange equation for pressure(P)

P=nRT/V
P=((0.400mol)*(0.0821 L*atm/mol*k)*(296k))/(0.200L) = 48.6 atm of pressure

Hope this helps you understand the concept and how to solve yourself in the future Thank you kindly!!!

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.