If I have an unknown quantity of gas at a pressure of 2.3 atm, a volume of 29 liters,
and a temperature of 360 K how many moles
of gas do I have? (Use R = 0.082057)

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?