Specific Heat Capacity

Explain what is meant by the specific heat capacity of a substance

Explain what is meant by the specific heat capacity of a substance?

The specific heat capacity is a quantity, for the amount of heat energy (joules) that causes one gram of the material to rise by one kelvin unit.

What are units are used to measure the specific heat capacity of a substance?

Specific heat capacity is measured in Jg^(-1) K^(-1) (or kJ〖 kg〗^(-1) K^(-1) ).

Compare the specific heat capacity of water with a range of other solvents.

Complete the following table

Substance Specific Heat Capacity ( Jg^(-1) K^(-1) )

Water 4.18

Ethanol 2.44

Benzene 1.05

Toluene 1.13

How does the specific heat capacity of water compare to the other substances in the table?

273

Calculate the heat energy that would be required to heat 2.00 L of water in a saucepan from 〖18.0〗^∙ C to 〖100.0〗^∙ C.

2.00 L of water = 2000 mL = 2000 g (assuming the density to be 1 g 〖mL〗^(-1)) Q=mC∆T C(H_2 O)=4.18 Jg^(-1) K^(-1) Q=2000 "x" 4.18 "x" (100.0-18.0) Q=2000 "x" 4.18 "x" 82.0 Q=685520 J Q=686 Kj

Explain how water’s ability to absorb heat is used to measure energy changes in chemical reactions

Water has the ability to absorb heat. Explain how this ability can be used to measure changes in chemical reactions.

Water can be used to calculated the release of energy in a chemical reaction. This is when, we know the mass of the unknown substance and the specific heat capacity of water. This is possible with other liquids (e.g. Ethanol), but water is a good liquid because of its high boiling point and minimal phase changes. An increase in temperature point to a change in energy; the temperature rising energy was released, if the temperature decreases energy was absorbed. Furthermore, the change in energy is directly proportional to the change in temperature of the water.

What is the difference between an endothermic and exothermic reaction? Give an example of each type of

Water’s high specific heat capacity is essential for all life, but especially for aquatic organisms. The temperature of an ocean is quite consistent and low, as water can absorb heat. This is not true for land. Thus, aquatic organisms are not required to face extreme temperatures, as most heat is absorbed by the grand masses of water. Furthermore, thanks to earth being 72% water, the temperature of earth is reduced. Likewise, most Australians live near the coast, due to the lower temperatures, allowing for a cooler lifestyle. As water evaporates, it absorbs energy and causes a cooling effect.

Explain what is meant by thermal pollution and discuss the implications for life if a body of water is affected by thermal pollution

What does the term thermal pollution mean?

The disposal of water into lakes and rivers which is hot enough to increase significantly the temperature of the water body.

Give one cause of thermal