Enthalpy practical write up

Water is a very good insulator of heat as its specific heat capacity is extremely large, larger than all other substances other than Ammonia. The specific heat capacity of water is 4.186 joule/grams ˚C. This means that it takes 4.186 joules of energy usually supplied in the form of heat to raise the temperature of 1 gram of water by 1 degree Celsius. This property allows water to moderate the earth’s climate as it can buffer large fluctuations in temperature

Hydrogen bonding forms inside liquid water when the hydrogen atoms of a water molecule are attracted towards the oxygen atoms of another different water molecule. Hydrogen bonding is an exceptionally strong intermolecular force that involves a major forces being a large dipole between a hydrogen atom and a highly electronegative atom. A major amount of energy is needed in overcoming the hydrogen bonding. Therefore more energy is needed to raise the temperature  

Heat flows between the system and the surrounds. If heat flows out of the system and into the surroundings this is known as an endothermic. The ice takes in the heat making the surroundings cold by also raising the temperature of the ice so that it melts. This reaction is most probably endothermic as ∆T is negative.

The larger ice cubes will have a larger volume but also a larger surface area. The larger ice cubes should theoretically melt slower and therefore have a smaller final temperature when the time limit of 20 minutes has ended.

Variables –

Control Used for Comparison – there is no control in this experiment

Apparatus-

• 1 ice cube tray with at least 10X 2cm by 2cm ice cubes
• 1 ice cube tray with at least 10X 4cm by 4cm ice cubes
• 1 bowl with a 10cm diameter for ice to melt in
• 1 Bunsen burner set at 2v to heat the bowl with the ice cubes in it
• 1 data studio on a laptop
• 1 data studio temperature probe

Safety Aspects – 

Protocol – 

Protocol diagram-

Procedure–

1. Pour water into an ice cube trays making sure that the water line is just below the brim of each individual ice cube capsule, remembering to do this for 1 x 1 cm, 2x2 cm, 3x3cm, 4x4 cm and 5x5cm ice cube trays.
2. Freeze until ice cubes are completely solid through or overnight
3. Once ice cubes are frozen  place one inside the bowl remembering to leave the other ice cubes in the freezer so that they will not melt
4. Once the ice cube is placed into the bowl measure the initial temperature of the ice cube.
5. Place bowl on top of hot plate and set to 2v
6. Heat the ice cube for 3 minutes
7. When the permitted time allowed for the ice to melt has ended, 3 minutes, measure the final temperature of the melted ice cube
8. Pour out melted ice water into the sink
9. Repeat steps 3-8 for 10 ice cubes of 1cm3, 4cm3, 9cm3, 16 cm3 and 25cm3
10. Use the formula q=m.Cs.∆T  to calculate heat transfer