p 1 = P0+h = 75+ 10 = 85(cmHg)
(2) Isobaric change of gas, L 1=5cm, L2=L+2=7cm, T 1=273+23=300(K).
According to Guy Lussac's law, there are:
L 1ST 1=L2ST2
Solution:
T2 = l2t 1l 1 = 7×3005k = 420k
Answer: (1) The pressure of the enclosed gas in the tube is 85cmHg；;
(2) Insert the glass tube into a container filled with liquid. When the length of the air column in the tube is 7 cm, its temperature is 420 K.