A $500 \mathrm{W}$ kettle contains $300 \mathrm{g}$ of water at $20 °\mathrm{C}$. Calculate the minimum time it would take to raise the temperature of the water to boiling point. 

 A mass of $20 \mathrm{g}$ of ice at $-15 °\mathrm{C}$ is taken from a freezer and placed in a beaker containing $200 \mathrm{g}$ of water at $26°\mathrm{C}$. Data for ice and water are given in Table $19.5.$

 Calculate the amount of thermal energy (heat) needed to convert all the ice at $-15 °\mathrm{C}$ to water at$0 °\mathrm{C}.$ 

A mass of $20 \mathrm{g}$ of ice at $-15 °\mathrm{C}$ is taken from a freezer and placed in a beaker containing 200 g of water at $26°\mathrm{C}$. Data for ice and water are given in Table.

Calculate the final temperature T of the water in the beaker assuming that the beaker has negligible mass.

An electric heater generating power of $120 \mathrm{W}$ is immersed in a beaker of liquid that is placed on a balance. When the liquid begins to boil it is noticed that the mass of the beaker and liquid decreases by $6.2 \mathrm{g}$ every minute.

State how this shows that the liquid is boiling at a steady rate. 

An electric heater generating power of $120 \mathrm{W}$ is immersed in a beaker of liquid that is placed on a balance. When the liquid begins to boil it is noticed that the mass of the beaker and liquid decreases by $6.2 \mathrm{g}$ every minute.

Calculate a value for the specific latent heat of vaporisation of the liquid.

An electric heater generating power of $120 \mathrm{W}$ is immersed in a beaker of liquid that is placed on a balance. When the liquid begins to boil it is noticed that the mass of the beaker and liquid decreases by $6.2 \mathrm{g}$ every minute. State and explain whether the value determined is likely to be larger or smaller than the accepted value.