A helium-filled balloon has a volume of 4.50 L when the temperature is 22.5 degrees C and the barometric pressure is 747.3 mmHg. The balloon’s volume is neither increasing nor decreasing, so what is the pressure of the helium inside the balloon? I feel like there's either not enough information here to solve or the answer is simply 747.3 mmHg, but I'm not sure at all. Any help would be much appreciated.

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.