Name______
Test: Water C 1-5
Matching(1-5)
1 The quantity or mass of solute which is dissolved in a given mass of solvent(usually in 100g of solvent or in ppm or as a percentage)
2 The substance which dissolves
3 Describes a solution in which no more solute could dissolve.
4 Describes the normal maximum concentration for a solute in a solvent (expressed as "____grams of solute/100grams of water") This property depends on temperature.
5 Capable of dissolving
a concentration
b solute
c soluble
d solubility
e saturated
6 . For gases dissolving in liquids , an increase in temperature______
a does not change solubility
b increases solubility
c decreases solubility
d makes solutions less concentrated
7 . For solids dissolving in liquids , an increase in temperature______
a does not change solubility
b increases solubility
c decreases solubility
d makes solutions less concentrated
8 . What is the greatest amount of KCl that may be dissolved in 100g of water at 50oC?
a 33 g
b 43 g
c 50 g
d 72g
e 82 g
9 . What temperature is needed to dissolve 130 g of KNO3 in 100 grams of water.
a 21oC
b 27oC
c 65oC
d 72oC
e 100oC
10 . Which substance has the lowest solubility at 0 oC ?
a KNO3
b KCl
c NaCl
d all are the same
11 . Water is saturated at 26 oC with oxygen. The temperature of the water is cooled to 8 oC. How much oxygen must be added to 1000g of water to keep it saturated?
a 1 mg
b 1 g
c 4 mg
d 4 g
e 7 mg
f 7 g
12 . Which of these would most greatly increase aeration ?
a decreasing the amount of sewage
b lowering the pH of the water
c removing heavy metals from the water
d placing a dam in a stream
e raising the water level of a stream
13 . FP&L removes water from the Intercostal to use in its electric power plant. The water leaving the power plant would
a be cooler and have a lowered oxygen concentration
b be warmer and have a lowered oxygen concentration
c be cooler and have a higher oxygen concentration
d be warmer and have a higher oxygen concentration
14 . Photosynthesis effects the amount of dissolved oxygen in water. Which statement is true
a it increases D.O. during the day
b it decreases D.O. during the day
c it increases D.O. during the night and day
d it decreases the D.O. during the night and day
15 . The process by which sewage and organic waste is consumed by aerobic bacteria is
a biodegradation which lowers D.O levels in streams
b biodegradation which raises D.O levels in a stream
c photosynthesis which lowers D.O levels in streams
d aeration which raises D.O levels in streams
e respiration which raises D.O levels in stream
Solubility and Concentration (5 points each)
Show all work, include units and report all numbers in significant digits.
16 What is the percent concentration of 30g acetic acid in 170g water?
17 How much potassium chloride will dissolve in 30 grams of water at 50 °C?
18 A solution which has .001 g of cadmium ion dissolved in 1000g of water is considered dangerous to human health. Calculate the concentration in ppm. Show work and units.
19 Convert 2.4ppm into parts per thousand (ppt).
20 What is the solution concentration in pph of water in a solution that contains 22g of sodium chloride and 160g of water?
21 If 60 grams of water are saturated at 70 °C with KNO3 and then cooled to 20°C, how much will precipitate?
Long Answer, do any 2 questions (each worth 5 points)
Answers should be in paragraph form and in complete sentences.
22 What is the predicted effect of temperature and pressure on the water solubility of solids? How would these effects differ for the water solubility of gases?
23 What effect does photosynthesis have on the amount of dissolved oxygen in water? What effect does aerobic bacteria have on the amount of dissolved oxygen in water?
24 Trout are considered a cold water fish. Explain why in terms of water temperature and dissolved oxygen.
25) Describe the location of saturated, unsaturated and supersaturated on the solubility graph.