Advertisements
Advertisements
Question
Hot air balloons float in the air because of the low density of the air inside the balloon. Explain this with the help of an appropriate gas law.
Advertisements
Solution
The working of a hot air balloon can be explained with the help of Charles’ law. According to Charles’ law, at constant pressure, the volume of a fixed amount of a gas varies directly with the temperature. This means that as the temperature increases, the air inside the balloon expands and occupies more volume. Thus, hot air inside the balloon is less dense than the surrounding cold air. This causes the hot air balloon to float in the air.
APPEARS IN
RELATED QUESTIONS
What would be the mass of CO2 occupying a volume of 44 litres at 25°C and 750 mm pressure.
Give reason for the following:
Gases have a lower density compared to solids or liquids.
Give reason for the following:
Gases exert pressure in all directions.
What is meant by aqueous tension? How is the pressure exerted by a gas corrected to account for aqueous tension?
Answer in one sentence.
A bubble of methane gas rises from the bottom of the North sea. What will happen to the size of the bubble as it rises to the surface?
Convert the following temperature from degree Celcius to kelvin.
−15° C
Convert the following temperature from degree Celcius to kelvin.
25° C
Convert the following temperature from degree Celcius to kelvin.
273° C
Match the pairs of the following:
| Column ‘A’ | Column ‘B’ |
| a. Boyle’s law | i. at constant pressure and volume |
| b. Charles’ law | ii. at constant temperature |
| iii. at constant pressure |
Write the statement for Boyle’s law
With the help of the graph answer the following -
At constant temperature, the Graph shows the relationship between pressure and volume. Represent the relation mathematically.
Solve the following.
The volume of a given mass of a gas at 0°C is 2 dm3. Calculate the new volume of the gas at constant pressure when the temperature is decreased by 10°C.
Solve the following.
A hot air balloon has a volume of 2800 m3 at 99°C. What is the volume if the air cools to 80°C?
The temperatures at which real gases obey the ideal gas laws over a wide range of pressure is called __________.
State Boyle's law.
Name two items that can serve as a model for Gay Lusaac’s law and explain.
Explain the following observation.
Liquid ammonia bottle is cooled before opening the seal
Of two samples of nitrogen gas, sample A contains 1.5 moles of nitrogen in a vessel of the volume of 37.6 dm3 at 298 K, and sample B is in a vessel of volume 16.5 dm3 at 298 K. Calculate the number of moles in sample B.
A small bubble rises from the bottom of a lake where the temperature and pressure are 6°C and 4 atm. to the water surface, where the temperature is 25°C and pressure is 1 atm. Calculate the final volume in (mL) of the bubble, if its initial volume is 1.5 mL.
Hydrochloric acid is treated with a metal to produce hydrogen gas. Suppose a student carries out this reaction and collects a volume of 154.4 × 10−3 dm3 of a gas at a pressure of 742 mm of Hg at a temperature of 298 K. What mass of hydrogen gas (in mg) did the student collect?
For a given mass of an ideal gas, which of the following statements is CORRECT?
A certain sample of gas has a volume of 0.2 L at one atmosphere pressure and 273.15 K. What is the volume of gas at 273.15°C at same pressure?
According to Andrews isothermals, the minimum temperature at which carbon dioxide gas obeys Boyles law is ______.
A certain mass of a gas occupies a volume of 2 dm3 at STP. At what temperature the volume of gas becomes double, keeping the pressure constant?
The volume of 400 cm3 chlorine gas at 400 mm of Hg is decreased to 200 cm3 at constant temperature. What is the new pressure of gas?
If 2 moles of an ideal gas at 546 K has volume of 44.8 L, then what will be it's pressure? (R = 0.082)
The number of molecules in 8.96 litres of gas at 0°C and 1 atm. pressure is approximately ______.
