1. -D. Tate March 12, 2009

6.  http://programs.northlandcollege.edu/biol ogy/Biology1111/animations/hydrogenbo nds.swf http://programs.northlandcollege.edu/biol ogy/Biology1111/animations/hydrogenbo nds.swf

9.  This means that most things will dissolve in water

11.  Solute + Solvent = Solution

15. 1 Swimmers find that they can float more easily in the ocean than in a freshwater pond. The most likely reason for this phenomenon is that the —  A viscosity of pond water is greater than that of ocean water  B density of ocean water is higher than that of pond water  C temperature of pond water is lower than that of ocean water  D mass of ocean water is greater than that of pond water

16. 2 The diagram shows physical changes that occur in the water cycle. Which of these shows condensation?  A Q  B R  C S  D T

17. 3 What characteristic of water remains the same no matter what is dissolved in it?  A The ratio of hydrogen to oxygen  B The ability to refract light  C The hydroxide ion concentration  D The freezing temperature

18. 4 Which would most likely cause the liquid in Tube A to rise?  A Starch concentrations being equal on each side of the membrane  B Water passing from a region of lower start concentration to one of higher starch concentration  C Water and starch volumes being the same  D Solute in the tubes changing from a higher temperature to a lower temperature

19. 5 If the properties of water were to change so that the solid form was denser than the liquid form, organisms living in a cold pond environment would be less likely to survive because water would no longer —  F dissolve enough oxygen from the air  G produce solutions containing vital nutrients  H remain neutral, instead becoming highly acidic  J produce a floating insulating layer of ice

20. 6 Which factor makes water an effective solvent?  F The presence of molecular oxygen  G Its lack of covalent bonds  H The polar nature of its molecules  J Its abundance on Earth’s surface

21. 7 Fish survive through severe winters because of the property of water that allows water to —  F form chemical bonds as it freezes, raising the water temperature below the ice  G increase in density while it freezes, dissolving more oxygen from the air  H expand when it freezes, creating a floating and insulating layer of ice  J precipitate vital nutrients when it freezes, increasing the food supply

22. 8 When a sea urchin egg is removed from the ocean and placed in freshwater, the egg swells and bursts. Which of these causes water to enter the egg?  F Coagulation  G Sodium pump  H Active transport  J Osmosis

23. 9 Water acts as a solvent of ionic compounds because –  F water is liquid over a wide range of temperatures  G water molecules are polar  H water is found in three states of matter  J water takes the shape of its container

24. 10 The diagram shows water molecules and ions from a NaCl crystal. What is the reason that each water molecule is arranged so that the oxygen part of the molecule faces a sodium ion?  A The oxygen in a water molecule contains a partial negative charge  B Gravity rotates the oxygen atoms to face the more massive sodium atoms  C Hydrogen atoms create repulsive forces with chloride ions  D Oxygen atoms form covalent bonds with sodium ions