We have two equal-size boxes, A and B. Each box contains gas that behaves as an ideal gas. We insert a thermometer into each box and find that the gas in box A is at 50o C while the gas in box B is at 10o C. This is all we know about the gas in the boxes. Which of the following statements ?must be true? Which ?could be true? Explain your reasoning. (a) The pressure in A is higher than in B. (b) There are more molecules in A than in B. (c) A and B do not contain the same type of gas. (d) The molecules in A have more average kinetic energy per molecule than those in B. (e) The molecules in A are moving faster than those in B.

Solution 33E Step 1: The size of box A and B is same. So, the volume is same for both. Temperature of box A is 50 C . Temperature of box B is 10 C . Both the boxes are filled with ideal gas, so the will obey the ideal gas equation. PV = constant × T ---------(1)