* not completed

. Which of the following properties of natural water is/are true? (Please select all that apply)

The alkali and alkaline earth elements are the most important (in quantity) metal ions in sea water correct incorrect

The largest form of fresh water in/on the Earth is groundwater correct incorrect

Water in lakes and rivers makes up about 3% of all water on Earth correct incorrect

Conservative elements have a long residence time in the oceans correct incorrect

A microlayer enriched in surface-active compounds is found on the ocean surface correct incorrect

* not completed

. Which of the following properties of natural water is/are true? (Please select all that apply)

The terms hypolimnion and thermocline are synonymous correct incorrect

Water moves from the atmosphere to the biosphere through photosynthesis correct incorrect

The concentration of oxygen in natural water is determined only by the temperature correct incorrect

In ocean water, the concentration-with-depth profile of nutrient elements often shows a decreasing trend correct incorrect

A process for removing soluble silicon from water involves some types of algae correct incorrect

* not completed

. Which of the following chemical properties of water is/are true? Please select all that apply.

Hydrogen bonds hold water molecules in ice together in an octahedral ring configuration correct incorrect

Breaking of hydrogen bonds in water during its phase transition from solid to liquid causes its density to decrease correct incorrect

The large value for enthalpy of fusion for water contributes to stable temperatures in local areas during winter season correct incorrect

The large enthalpy of vapourization is related to the requirement to break hydrogen bonds as evaporation occurs correct incorrect

When water vapour is in equilibrium with liquid water, the humidity is 100% correct incorrect

* not completed

. Which of the following statements about natural water is/are true? (Please select all that apply)

Liquid water becomes less dense as the temperature decreases from 4^oC to 0^oC because water has a large dipole moment correct incorrect

The section of the Earth's surface where soil is partially filled with water is called the phreatic zone correct incorrect

Autoprotolysis of water is an exothermic process correct incorrect

The mixing ratio of water in the atmosphere is usually greater than the equilibrium value due to rapid mixing of air masses correct incorrect

Water moves from the biosphere to the atmosphere through transpiration correct incorrect

* not completed

. Which of the following statements about natural water is/are true?  (Please select all that apply)

For a lake containing sulfate at a level of 7.0 μmol L^-1_, when expressed using the ppb unit, the number expressing concentration will be greater for sulfate than for sulfur correct incorrect

Concentrations of dissolved species in lake water, measured as μg L^-1 will be nearly identical to those measured as μg kg^-1 correct incorrect

A concentration value expressed as mg L^-1 will be the same as one expressed as μg m^-3 correct incorrect

Measuring total organic carbon values in water should always be done using molar units correct incorrect

For water, concentration expressed as ppb and for air, concentration expressed as ppbv measure μg of constituent in 1 L of water or air respectively correct incorrect

* not completed

. According to Figure 9.1, lakes make up approximately: (Please select all that apply)

67% of fresh water correct incorrect

27% of fresh water correct incorrect

67% of accessible surface water correct incorrect

0.27% of fresh water correct incorrect

0.008% of Earth's water correct incorrect

* not completed

. Based on data in Table 9.1, and Appendix A.1 and B.1 the composition of sea water includes: (Please select all that apply)

Sodium at a concentration of 10 920 mg L^-1 correct incorrect

Sodium at a concentration of 10 760 mg kg^-1 correct incorrect

Fluoride at a concentration of 1 ppm correct incorrect

Chloride at a concentration of 0.55 mol L^-1 correct incorrect

Sodium at a concentration of 0.47 mol L^-1 correct incorrect

* not completed

. Which of the following statements about the redox properties of water (at 25°C) is/are true? (Please select all that apply)

Redox properties of water play an important role in the chemistry of materials dissolved in water correct incorrect

The upper limit of redox potential for water at pH 10 is approximately 0.64 V correct incorrect

The lower limit of redox potential of water at pH 5 is approximately -0.30 V correct incorrect

Hydrogen gas is a product of the reduction of water only under acidic conditions correct incorrect

An E/pH diagram for water shows the regions where water is stable  correct incorrect

* not completed

. What is the mixing ratio of water in the atmosphere at 30°C, 101 kPa and 80% humidity?

4.2 kPa correct incorrect

2.3% correct incorrect

40.6 g m^-3 correct incorrect

3.3% correct incorrect

80.8% correct incorrect

* not completed

. Which of the following statements regarding a 5.5x10^-5 M SO₄^2- solution is/are true? (Please select all that apply)

One litre of solution contains 0.00176 g of S correct incorrect

The concentration of S is 1.76 ppm correct incorrect

The concentration of sulphate is 5.28 ppm correct incorrect

A factor of 3 can be used to convert from the mass of S to the mass of SO₄^2- correct incorrect

The molar concentration would not change if all the sulfate were reduced to sulfide correct incorrect