Question

Physics 119 General Physics II Winter 2019 Assigament 2 Due Thursday, January 31 For the whole assignment, remember, as with everything, neatness counts. Conceptual Questions: These questions are to be answered with a short para- graph. You will be graded on the physics content of your answer as well as on its structure and conciseness. Problem 1. Which statement below is true (choose only one): (a) A mol of any gas has different volume than a mol of any other gas (at same pres- sure and temperature), or in other words their molar volumes are different. (b) A mol of any substance has the same mass as a mol of any other substance. (c) The units for the Avogadro's number are grams per mol. (d) A mol of any substance contains the same number of particles as a mol of any other substance. (e) There are more molecules in a mol of H2O than in a mol of CO. Problem 2. What is the temperature of 100g of gas (molar mass 44.01 g/mol) occupying a volume of 55 L at a pressure of 1.0 atm. Problem 3. Some amount of ideal gas is kept at constant pressure by means of a freely movable piston. How would you change its temperature in order to have the volume halved? (a) The temperature must be doubled. (b) The temperature must be halved too. (c) The temperature must not be changed. (d) The temperature must be decreased with 50°C (e) There is not enough information given to solve the problem. Problem 4. At 20°C, would there be more or less air mass in a room than at oPC

Answer 1

1)d

1 mole of any substance contains Avogadro number(6.02*10^23) of particles

2)using ideal gas eqn

Pv=nRT

10^5*55*10^-3=(100/44.01)*8.314*T

T=291.14K

3)For constant pressure process V is directly proportional to temperature.

so in order to half the volume temperature must be halved.

4)Mass is independent of temperature.Both will have same mass.