Which of these is caused by a chemical change?
a. the honey in a jar crystallizes and will no longer pour.
b. the skin of a banana turns from green to yellow as it ripens.
c. a box of powdered brown sugar turns into a solid brick over time.
d. the salt crystals in a shaker cake and will no longer pour easily.?

The air in an automobile tire with a volume of 2.60 ft3 is at 70°f and 21 psig. determine the amount of air that must be added to raise the pressure to the recommended value of 30 psig. assume the atmospheric pressure to be 14.6 psia and the temperature and the volume to remain constant. the gas constant of air is ru = 53.34ft⋅lbflbm⋅r(1 psia144 lbf/ft2) = 0.3704 psia⋅ft3lbm⋅r the amount of air that must be added to raise the pressure is lbm