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प्रश्न
Choose the most correct option.
Pressure cooker reduces cooking time for food because _______.
पर्याय
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
उत्तर
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.
संबंधित प्रश्न
Answer the following.
How vapour pressure lowering is related to a rise in the boiling point of solution?
Answer the following.
Why vapour pressure of a solvent is lowered by dissolving a nonvolatile solute into it?
The following solution/solvent has maximum vapour pressure _______.
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.
The vapour pressure of a pure liquid is 0.043 bar at a certain temperature. When a nonvolatile solute is dissolved into it, the vapour pressure of the solution is found to be 0.041 bar. What is the relative lowering of vapour pressure?
For a very dilute solution, the osmotic pressure is given by π = n2RT/V where V is the volume in L containing n2 moles of nonvolatile solute. Establish the equation for molar mass of solute.
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.
The vapour pressure of pure solvent and solution are 120 mm Hg and 108 mm Hg respectively. The mole fraction of the solvent in the solution is ____________.
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?
The vapour pressure of pure benzene (molar mass 78 g/mol) at a certain temperature is 640 mm Hg. A nonvolatile solute of mass 2.315 g is added to 40 g of benzene. The vapour pressure of the solution is 600 mm Hg. The molar mass of solute is ____________.
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 ____________.
The vapour pressure of water at 20°C is 17 mm Hg. The vapour pressure of solution containing 2.8 g urea in 50 g of water is ____________.
Which of the following changes will cause increase in vapour pressure of 1 molal aqueous KI solution at same temperature?
Identify the correct statement from the following:
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 ______.
The vapour pressure of a solvent A is 0.80 atm. When a non-volatile substance B is added to this solvent its vapour pressure drops to 0.6 atm. the mole fraction of B in the solution is ______.
Calculate the mole fraction of solute, if the vapour pressure of pure benzene at a certain temperature is 640 mmHg and the vapour pressure of a solution of a solute in benzene is 600 mmHg.
State and explain Raoult's law for the solution of non-volatile solutes.
