A tire at 21°C has a pressure of 0.82 atm. Its temperature decreases to - 3.5°C. If there is no volume change in the tire, what is the pressure after the temperature change?

Using ideal gas equation, PV = nRT, and since there is no volume change and amount change, the equation is now P = kT, where k = nR/V. Temperature must be in kelvin From the given, k = (0.82) / (21 + 273) = 2.78 x 10^-3 Substituting T = - 3.5+273, P = 0.75 atm