Question

1.

(a) How many molecules are present in a sample of an ideal gas that occupies a volume of 2.10 cm3, is at a temperature of 20°C, and is at atmospheric pressure?

(b) How many molecules of the gas are present if the volume and temperature are the same as in part (a), but the pressure is now 3.00 ✕ 10−11 Pa (an extremely good vacuum)?

2.

An air bubble released by a submersible vehicle, 120 m below the surface of a lake, has a volume of 1.55 cm³. The surface of the lake is at sea level, and the density of the lake water can be approximated as that of pure water. As the bubble rises to the surface, the temperature of the water and the number of air molecules in the bubble can each be approximated as constant. Find the volume (in cm³) of the bubble just before it pops at the surface of the lake.

Answer 1

O a v= 2 locum? - 2.10 xloob n? T= 200 = 20+273 k= 293k. P- Patin = I aton = 101325 Pa. By ideal gas equi: Pr = nRT na pu (101325) (2.10x10=) (8.314) (293) - 8.73010 notes . No of molecules - .X NA Avogadro's no. = (8.73 410-S) (6.0 22x10 23) - (5.26 x 1019 molecules Now, P= 34667" Pa to (316") (2.10 81662 - 8.314 x 293 - 2.59 x 10-20 notes : No. of molecules = (2.59*10-2) (6.022 790.237 (6)

Please post the other question separately. Thanks and good luck:)