Question

1. You have 0.23 moles of an ideal gas. You measure that the pressure of the gas is 1.7 atm and that the volume is 1000 cm³. What is the temperature of this gas in ºC?

–146 ºC

–273 ºC

–200 ºC

–183 ºC

+73.4 ºC

2.

In the Specific Heat of Solids lab, you were to determine what Mystery #3 Sample was by using calorimetry. What type of metal did you find Mystery #3 to be?

Iron.

Tungsten.

Copper.

Titanium.

Aluminum.

3.

What is the difference between heat capacity and specific heat?

The heat capacity depends on the mass of the material, the specific heat does not.

The specific heat depends on the mass of the material, the heat capacity does not.

There is no difference.

The specific heat refers to the amount of heat released or absorbed when a material changes state, the heat capacity refers to the amount of heat a material can store.

4.

Resistors of 2.0 Ω, 4.0 Ω, and 6.0 Ω are all hooked up in parallel to a 12 V battery (all four circuit elements are in parallel with one another). The current that goes through the 2.0 Ω resistor is:

2.0 Amps.

6.0 Amps.

1.2 Amps.

1.0 Amp.

0.25 Amps.

Answer 1

(1) Pressure of the gas = P = 1.7 atm = 1.7 x 1.01325 x 10⁵ Pa,

volume of the gas = V = 1000 cm³ = 10^-3 m³,

mole number = n = 0.23,

and, R = 8.314 J / ( mol . K ) is the universal gas constant.

Hence, if T be the absolute temperature of the gas, then, according to the ideal gas law,

PV = nRT

or, T = PV / nR = { 1.7 x 1.01325 x 10⁵ x 10^-3 / ( 0.23 x 8.314 ) } K = 90 K = ( 90 - 273 )^o C = - 183^o C.

Hence, correct option is : - 183^o C.

(3) Correct option is :

The heat capacity depends on the mass of the material, the specific heat does not.

(4) Since the resistors are connected in parallel, each of them has a potential difference of 12 V across.

So, current in the 2 resistor is : 12 V / 2 = 6 Amps.

Hence, correct option is : 6.0 Amps.