Heat Capacity of H2O

• Water has the second highest molar specific heat capacity of any known substance, after ammonia, which is a result of the extensive hydrogen bonding between its molecules.

• This unusual property allows water to moderate Earth's climate by buffering large fluctuations in temperature.

• Earth’s water bodies act as heat sinks by dissipating heat from the atmosphere and carrying it around the world via ocean currents.

This large heat capacity acts to buffer temperature changes in the atmosphere, while ocean circulation redistributes heat around the globe and

influences regional climates.

Heat Capacity Calculations

• q=mc∆T

• q = heat energy gained J

• m = mass of the substance g

• c = specific heat capacity J/gºC

• ∆T = change in temperature ºC

Practice Problems

• Using the formula q=mc∆T solve the following problems:

• 1. 5g of water was heated from 20ºC to 80ºC. How much energy was used to heat the H2O? *cH2O = 4.18 J/gºC

• 2. If a 3.1g ring is heated using 10.0 J, it’s temperature rises by 17.9ºC. Calculate the specific heat capacity of the ring. Is the ring pure gold? *cAu = 0.13 J/gºC

The Hydrosphere

Water, Water, Everywhere!

Water, Water, Everywhere!

• 96.5% - Global oceans

• 1.7% - Polar icecaps, glaciers, and permanent snow

• 1.7% - Groundwater, lakes, rivers, streams, and soil

• Only a thousandth of 1% of the water on Earth exists as water vapor in the atmosphere.

Water Vapor

• Water vapor is a powerful greenhouse gas, and it is a major driver of the Earth’s weather and climate as it travels around the globe, transporting latent heat with it.

• Latent heat is heat obtained by water molecules as they transition from liquid or solid to vapor; the heat is released when the molecules condense from vapor back to liquid or solid form, creating cloud droplets and various forms of precipitation.

3 Stages

A Multi-Phased Journey

Continuous exchange of moisture between the oceans, atmosphere, and land