1.
A balloon occupies a volume of 2.0 L at 40^{o}C. How much volume will it occupy at 30^{o}C?
Correct Answer
B. 1.94 L
Explanation
Using the formula,
V1/T1=V2/T2 and substituting the values of V1,T1 and T2 and solving the equation we get,
Given:
V1â€‹=2.0L at T1â€‹= 40°C =313.15K
T2=30°C =303.15 K
2.0L/313.15K=V2/313.15K
Therefore
V2=2.0L x 303.15K/313.15K
V2â€‹≈1.94L
2.
What is the final pressure in a balloon when the volume is changed from 1.5 L to a volume of 2.5L at constant temperature? (Initial pressure is 1.1 atm).
Correct Answer
A. 0.66 atm
Explanation
To find the final pressure (Pf) when the volume changes at constant temperature, you can use Boyle's Law, which states that the product of pressure and volume is constant for a given amount of gas at constant temperature.
The formula for Boyle's Law is given by:
P1 . V1 = P2 . V2
where:
- ( P1) is the initial pressure,
- (V1) is the initial volume,
- ( P2) is the final pressure,
- ( V2) is the final volume.
Given:
- (P1 = 1.1 ) atm (initial pressure),
- ( V1 = 1.5 ) L (initial volume),
- ( V2= 2.5 ) L (final volume).
Plug in the values into Boyle's Law:
[ 1.1. 1.5] L = P2 . 2.5 L
Now, solve for P2
P2 = 1.1 atm . 1.5L/ 2.5L
P2 ≈ 0.66 atm
Therefore, the final pressure in the balloon when the volume changes from 1.5 L to 2.5 L at constant temperature is approximately 0.66 atm.
3.
Gas in a balloon occupies 3.3 L. What volume will it occupy if the pressure is changed from 100 kPa to 90 kPa (at constant temperature of 310 K (about room temperature)?
Correct Answer
C. 3.67 L
Explanation
The formula for Boyle's Law is given by:
P1 . V1 = P2 . V2
where:
- ( P1) is the initial pressure,
- (V1) is the initial volume,
- ( P2) is the final pressure,
- ( V2) is the final volume.
Given:
- P1 = 100 kPa (initial pressure),
- V1 = 3.3 L (initial volume),
- P2 = 90 kPa (final volume)
T = 310K (Constant Temperature)
Plug in the values into Boyle's Law to find V2:
V2 = P1 . V1 / P2
Now, solve for V2
V2 =100 kPa . 3.3L/ 90kPa
V2 ≈ 3.67L
Therefore, the volume the gas will occupy when the pressure is changed from 100 kPa to 90 kPa at constant temperature is approximately 3.67 L.
4.
What is the final pressure in a vessel when the volume is changed from 1.3 L to a volume of 1.55 L at constant temperature? (Initial pressure is 1.5 atm).
Correct Answer
A. 1.26 L
Explanation
The formula for Boyle's Law is given by:
P1 . V1 = P2 . V2
where:
- ( P1) is the initial pressure,
- (V1) is the initial volume,
- ( P2) is the final pressure,
- ( V2) is the final volume.
Given:
- (P1 = 1.5 ) atm (initial pressure),
- ( V1 = 1.3 ) L (initial volume),
- ( V2= 1.55 ) L (final volume).
Plug in the values into Boyle's Law:
[ 1.5. 1.3] L = P2 . 1.55 L
Now, solve for P2
P2 = 1.5 atm . 1.3L/ 1.55L
P2 ≈1.26atm
Therefore, the final pressure in the vessel when the volume changes from 1.3 L to 1.55 L at constant temperature is approximately 1.26 atm.
5.
A balloon occupies 3.2 L at 37^{o}C. How much volume will it occupy at 42^{o}C?
Correct Answer
A. 3.25 L
Explanation
Using the formula,
V1/T1=V2/T2 and substituting the values of V1,T1 and T2 and solving the equation we get,
Given:
V1â€‹=3.2L at T1â€‹= 37°C =310.15K
T2=42°C =315.15 K
3.2L/315.15K=V2/310.15K
Therefore
V2=3.2L x 310.15K/315.15K
V2â€‹≈3.25L
Therefore, the balloon will occupy approximately 3.25 L at 42°C.
6.
A gas occupies a balloon with a volume 2.0 L at 33^{o}C. How much volume will it occupy at 37^{o}C, if pressure remains constant?
Correct Answer
C. 2.026 L
Explanation
Using the formula,
V1/T1=V2/T2 and substituting the values of V1,T1 and T2 and solving the equation we get,
Given:
V1â€‹=2.0L at T1â€‹= 33°C =306.15K
T2=37°C =310.15 K
2.0L/306.15K=V2/310.15K
Therefore
V2=2.0L x 310.15K/306.15K
V2â€‹≈2.026L
Therefore, the balloon will occupy approximately 2.026 L at 37°C.
7.
A gas expands from a volume 2.0 L at 36^{o}C to a volume of 2.5 L. What is the final temperature (in Kelvin) if the pressure is constant?
Correct Answer
A. 386.43 K ( which equals 113.25 Celsius)
Explanation
Using the formula,
V1/T1=V2/T2 and substituting the values of V1,T1 and V2 and solving the equation we get,
Given:
V1â€‹=2.0L at T1â€‹= 36°C =309.15K
V2=2.5L
2.0L/309.15K=2.5L/T2
Therefore
T2=2.5L x 309.15K / 2.0 L
T2â€‹≈ 386.43 K
Therefore, the final temperature is approximately 386.43 K when the gas expands from a volume of 2.0 L at 36°C to a volume of 2.5 L, assuming the pressure remains constant.
8.
If the air inside a balloon is heated, the volume will:
Correct Answer
A. Increase
Explanation
If the air inside a balloon is heated while the pressure remains constant, the volume of the balloon will generally increase. This behavior follows Charles's Law, which states that the volume of a gas is directly proportional to its temperature at constant pressure.
9.
The kinetic theory of gasses, which of the following is important for an ideal gas:
Correct Answer
A. There is no attraction or repulsion between the gas molecules, whereas there is attraction between molecules of liquids or solids.
Explanation
The correct answer is that there is no attraction or repulsion between the gas molecules, whereas there IS attraction between molecules of liquids or solids. This is important for an ideal gas because it assumes that the gas molecules do not interact with each other, except during collisions. This allows for simplifications in the mathematical models used to describe the behavior of ideal gasses. In contrast, liquids and solids have intermolecular forces that result in attractions between their molecules, leading to different behaviors and properties.
10.
Which of the following describes the relationship between P and V?
Correct Answer
B. Inversely proportional
Explanation
The relationship between P and V is described as inversely proportional. This means that as one variable (P) increases, the other variable (V) decreases, and vice versa. In other words, there is a negative correlation between P and V, where an increase in one variable corresponds to a decrease in the other variable.