Advertisements
Advertisements
Question
Choose the most correct option.
Pressure cooker reduces cooking time for food because _______.
Options
boiling point of water involved in cooking is increased
heat is more evenly distributed in the cooking space
the higher pressure inside the cooker crushes the food material
cooking involves chemical changes helped by a rise temperature
Advertisements
Solution
Pressure cooker reduces cooking time for food because boiling point of water involved in cooking is increased.
Explanation:
The boiling point of a substance is the temperature at which the vapour pressure of a liquid equals the pressure surrounding the liquid and the liquid changes to vapour.
Normally, when we cook food, the temperature inside rises until the water begins to boil. The temperature of the system will not rise at boiling point because heat is utilised to boil the water.
However, when we cook food in a pressure cooker, the temperature at which water boils rises as the pressure within the pressure cooker rises.
As the surrounding pressure rises, so does the boiling point temperature. As a result, instead of boiling the water, the heat will raise the temperature of the system. Food cooks faster at higher temperatures because cooking reactions speed up.
RELATED QUESTIONS
Answer the following.
How vapour pressure lowering is related to a rise in the boiling point of solution?
According to Raoult’s law, relative lowering of vapour pressure of solution containing dissolved nonvolatile solute _______.
Write the expression for relative lowering of vapour pressure.
Give two points to explain why vapour pressure of solvent is lowered by dissolving nonvolatile solute into it.
Which of the following is NOT a colligative property?
The vapour pressure of solvent decreases by 1 O mm Hg, if mole fraction of non-volatile solute is 0.2. Calculate vapour pressure of solvent.
Which of the following is CORRECT for a solution containing non-volatile solute in it?
In an experiment, 1 g of a non-volatile solute was dissolved in 100 g of acetone (molar mass = 58 g mol−1) at 298 K. The vapour pressure of the solution was found to be 192.5 mm Hg. The molecular weight of the solute is (vapour pressure of acetone = 195 mm Hg) ____________ g mol−1.
Which of the following is CORRECT statement?
At a constant volume, a quantity of an ideal gas has a pressure of 700 mm Hg at 300 K. At what pressure, the temperature will be halved?
According to Raoult's law, relative lowering of vapour pressure for a solution containing a nonvolatile solute is equal to ____________.
Relative lowering in vapour pressure of a solution containing non-volatile solute is the ratio of ____________.
Which of the following is INCORRECT expression in terms of vapour pressure of pure solvent `("P"_1^0)` and that of solution (P)?
What will be the molar mass of solute if vapour pressure of pure benzene is 450 mm Hg when 1.5 g of non-volatile solute is added to 30 g of benzene?
(Vapour pressure of solution= 400 mm Hg, Atomic mass C = 12, H = 1)
Relative lowering in vapour pressure depends on _______.
Identify the correct statement from the following:
38.4 g of unknown substance (molar mass 384 g mol-1) and 116 g of acetone is used to prepare a solution at 313 K. If vapour pressure of pure acetone (molar mass 58 g mol-1) is 0.842 atmosphere, what is the vapour pressure of solution?
12 g of a nonvolatile solute dissolved in 108 g of water produces the relative lowering of vapour pressure of 0.1. The molecular mass of the solute is ______.
Which of the following solutions will have the maximum lowering of vapour pressure at 300 K?
State and explain Raoult's law for the solution of non-volatile solutes.
