A 1000W heater is placed in an insulated beaker containing 750g of water at 100 ∘ C. The water vapour is allowed to escape. Assume that there is no loss to the surroundings via conduction, convection or radiation. The specific latent heat of vaporisation of water is 2260kJ/kg.Part AWater leftAll questions in this part are answered correctlyHow much water is left after 5.0minutes?Value?UnitskgCorrect!Hint 1Hint 2Hint 3Part BHalf evaporatedHow long will it take for half of the water to have evaporated? Give your answer to the nearest second.

To solve this problem, we need to understand the concept of latent heat. Latent heat is the heat absorbed or released by a substance during a phase change from a gas to a liquid or a liquid to a solid while maintaining a constant temperature. In this case, we are dealing with the latent heat of vaporization, which is the heat required to change a liquid into a gas at the same temperature.

Part A:

First, we need to calculate the total energy supplied by the heater in 5 minutes.

The power of the heater is 1000W, which is equivalent to 1000J/s.

So, in 5 minutes (or 300 seconds), the total energy supplied is 1000J/s * 300s = 300,000J.

Next, we need to calculate how much water can be vaporized by this amount of energy.

The specific latent heat of vaporization of water is 2260kJ/kg, which is equivalent to 2260000J/kg.

So, the mass of water that can be vaporized is 300,000J / 2,260,000J/kg = 0.133kg.

The initial mass of the water is 750g, or 0.75kg.

So, the mass of water left after 5 minutes is 0.75kg - 0.133kg = 0.617kg.

Part B:

To find out how long it will take for half of the water to have evaporated, we first need to calculate the energy required to vaporize half of the water.

Half of the water is 0.75kg / 2 = 0.375kg.

The energy required to vaporize this amount of water is 0.375kg * 2,260,000J/kg = 847,500J.

The power of the heater is 1000W, or 1000J/s.

So, the time required is 847,500J / 1000J/s = 847.5s.

Rounding to the nearest second, it will take approximately 848 seconds for half of the water to have evaporated.