Advertisements
Advertisements
प्रश्न
Water boils at 120 °C in a pressure cooker. Explain the reason.
Advertisements
उत्तर
- The boiling point of a liquid rises with increased pressure and falls with decreased pressure. At one atmosphere pressure, pure water has a boiling point of 100°C.
- A pressure cooker does not allow steam to escape. Because of the increased pressure, the vapor pressure on the water inside the cooker rises to approximately 1.75 times that of the atmosphere, causing water to boil at around 120°C to 125°C.
संबंधित प्रश्न
Differentiate between heat capacity and specific heat capacity.
Write the approximate value of specific heat capacity of water in S.I. unit.
Water property of water makes it an effective coolant?
How will global warming disturb the ecological balance?
Solve the following problems:
Equal heat is given to two objects A and B of mass 1 g. Temperature of A increases by 3°C and B by 5°C. Which object has more specific heat? And by what factor?
104g of water at 30°C is taken in a calorimeter made of copper of mass 42 g. When a certain mass of ice at 0°C is added to it, the final steady temperature of the mixture after the ice has melted, was found to be 10°C. Find the mass of ice added. [Specific heat capacity of water = 4.2 Jg–1°C–1 ; Specific latent heat of fusion of ice = 336 Jg–1; Specific heat capacity of copper = 0.4 Jg–1°C–1] .
Write an expression for the heat energy liberated by a hot body.
Discuss how high specific heat capacity of water helps in formation of land and sea breeze.
A. hot solid of mass 60 g at 100°C is placed in 150 g of water at 20° C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg-1 °C-1]
Prove the Mayer's relation `C_p - C _v = R/J`
