4.2 Solutions

Question 1

1. Which item from the following list is an electrolyte?
   A. Ca2+
   B. Oxygen gas (O2) dissolved in water
   C. Table salt (solid form of Na+Cl−)
   D. Glucose (solid form of the sugar)

Answer 1

Answer is C: “An electrolyte is a substance that when dissolved in water, will produce ions in solution.” Glucose is a molecular compound so does not ionise.

Question 2

2. Given that 1 mol of Na+Cl− has a mass of 58.5 g, how many grams of Na+Cl− are dissolved in a solution of 0.1 mol per litre?
   A. 0.585 g
   B. 5.85 g
   C. 58.5 g
   D. 0.1 g

Answer 2

Answer is B: 0.1 mol = 1/10 of 58.5 g = 5.85 g

Question 3

3. How many grams of sodium chloride are there in (0.9%) normal saline?
   A. 0.09 g per 100 ml
   B. 0.09 g per litre
   C. 9 g per 100 ml
   D. 9 g per litre

Answer 3

Answer is D: 0.9% means 0.9 g per 100 ml of solution = 9 g per 1000 ml (i.e. per litre)

Question 4

4. How many grams of sodium chloride are there in a 1 L bag of 0.9% saline?
   A. 0.09 g
   B. 0.9 g
   C. 9 g
   D. 90 g

Answer 4

Answer is C: 0.9% means 0.9 g per 100 ml of solution = 9 g per 1000 ml (i.e. per litre)

Question 5

5. What is the percentage concentration of glucose if 80 gram of glucose is dissolved in 1 L of solution?
   A. 0.8%
   B. 5%
   C. 8%
   D. 80%

Answer 5

Answer is C: 80 g per 1000 ml = 8 g per 100 ml = 8%

Question 6

6. Given that the concentration of hydronium ions in a solution with pH of 2 is 0.19%, what would be the concentration of hydronium ions in a solution with pH of 3?
   A. 0.13%
   B. 0.29%
   C. 0.019%
   D. 1.9%

Answer 6

Answer is C: A pH change of one corresponds to a change in hydronium ion concentration by a factor of 10. As the pH has risen, the acidity has decreased, so there are fewer hydronium ions. That is 1/10 of 0.19% = 0.019%

Question 7

7. What does the term “electrolyte” refer to?
   A. An uncharged dissolved particle
   B. The smallest particle of an element
   C. A substance that will conduct electricity when dissolved in water
   D. Negatively charged subatomic particles

Answer 7

Answer is C: This is the definition of an electrolyte.

Question 8

8. What is meant by referring to a solution concentration of 0.18%?
   A. 0.18 g of solute in 100 ml of solution
   B. 1.8 g of solute in 100 ml of solution
   C. 0.18 g of solute in 1 L of solution
   D. 0.18 mol of solute in 100 ml of solution

Answer 8

Answer is A: 0.18% means 0.18 g per 100 ml of solution

Question 9

9. Which of the following is NOT an electrolyte (or does not contain
   electrolytes)?
   A. Cl−
   B. Acetic acid
   C. Glucose
   D. A 0.9% solution of sodium chloride

Answer 9

Answer is C: Glucose will dissolve in water, but being a molecular compound, it does not produce ions.

Question 10

10. If the concentration of a solution is 5%, which of the following is true?
    A. There is 0.5 g of solute per 100 ml of solution.
    B. There is 5 g of solute per 100 ml of solution.
    C. There is 5 g of solute per 1000 ml of solution.
    D. There is 50 g of solute per 100 ml of solution.

Answer 10

Answer is B: 5% = 5% = 5 per hundred = 5 g per 100 ml of solution.

Question 11

11. What does the term “electrolyte” refer to?
    A. The minor component of a solution
    B. A substance that will conduct electricity when dissolved in water
    C. The smallest particle of an element
    D. Negatively charged subatomic particles

Answer 11

Answer is B: This is a definition of electrolyte.

Question 12

12. The solution concentration 0.9% means that there are:
    A. 0.9 g of solute in 100 ml of solution
    B. 9.0 g of solute in 100 ml of solution
    C. 0.9 g of solute in 1 L of solution
    D. 0.9 mol of solute in 100 ml of solution

Answer 12

Answer is A: 0.9% = 0.9% = 0.9 per hundred = 0.9 g per 100 ml of solution.

Question 13

13. Which of the following is NOT an electrolyte (or does not contain
    electrolytes)?
    A. K+
    B. Nitrate ions
    C. Haemoglobin
    D. A 1% solution of sodium chloride

Answer 13

Answer is C: Haemoglobin is an uncharged protein found within red blood cells.

Question 14

14. Which is the best definition of an electrolyte?
    A. An atom that dissociates into ions
    B. A substance that will conduct electricity when it is dissolved in water
    C. Molecules of solid, liquid or gas that will conduct electricity in solution
    D. A substance that will conduct electricity

Answer 14

Answer is B: This is a definition of electrolyte. Choice C is restricted to molecules; and there must be a solution involved, so D is wrong

Question 15

15. What is the condition known as hyperkalaemia characterised by?
    A. Higher than normal concentration of potassium in the blood
    B. Lower than normal concentration of potassium in the blood
    C. Serum sodium concentration greater than 150 mmol/L
    D. Serum sodium concentration greater than 5 mmol/L

Answer 15

Answer is A: Kalaemia refers to potassium. “Hyper-” refers to more or an excess.

Question 16

16. A solution of 5% glucose is used for an infusion. Over a 2 h period, 300 ml of
    the solution were used. How much glucose in grams was infused?
    A. 5 g
    B. 12.5 g
    C. 15.0 g
    D. 50 g

Answer 16

Answer is C: 5% means 5 g per 100 ml. So in 300 ml there would be 3×5 g = 15 g infused.

Question 17

17. A solution of glucose is used for an infusion. Over a 3-h period, 250 ml of solution is used containing a total of 5 g of glucose. What is the concentration of the glucose solution used?
    A. 2%
    B. 20%
    C. 0.2%
    D. 5%

Answer 17

Answer is A: 5 g per 250 ml = 20 g per 1000 ml (multiply by 4) = 2 g per 100 ml = 2%.

Question 18

18. A sudden and severe loss of potassium due to diuretic abuse is likely to result
    in:
    A. Hypothermia
    B. Hyponatremia
    C. Hypokalaemia
    D. Hypoventilation

Answer 18

Answer is C: Kalium means potassium; the prefix “hypo-” means a lack or decrease in.

Question 19

19. Which of the following statements relating to a patient with severe loss of potassium due to diuretic abuse is TRUE?
    A. The serum levels of potassium are >3 mmol/L.
    B. An ECG is probably not warranted.
    C. The condition may be treated by administering oral glucose and
    potassium.
    D. One course of action is to decrease the intake of potassium and to undergo ion-exchange resin treatment.

Answer 19

Answer is C: A loss of potassium may be treated by administering potassium. Hypokalaemia refers to a blood concentration of <3 mmol/L, and such a level could affect the heart so an ECG IS warranted

Question 20

20. Which strategy would be most effective in dealing with a severe case of dehydration?
    A. Oral administration of a hypertonic solution
    B. Intravenous administration of distilled water
    C. Intravenous administration of isotonic glucose
    D. Intravenous administration of hypotonic sodium chloride

Answer 20

Answer is C: IV solutions should be isotonic (oral solutions should be hypotonic). Glucose would be absorbed by cells leaving the water behind in the blood which would reduce blood osmolarity. Hence water would redistribute itself by osmosis
through the body.

Question 21

21. A common IV solution is the combination 0.18% sodium chloride and 4% glucose (also called “4% and a fifth”). How many grams of each solute will be in a 1 L bag?
    A. 0.18 g of sodium chloride and 4 g of glucose
    B. 0.9 g of sodium chloride and 5 g of glucose
    C. 1.8 g of sodium chloride and 40 g of glucose
    D. 18 g of sodium chloride and 40 g of glucose

Answer 21

Answer is C: 0.18% sodium chloride and 4% glucose means 0.18 g of sodium chloride per 100 ml and 4 g of glucose per 100 ml. So in 1 L there would be 1.8 g and 40 g, respectively

Question 22

22. The “extracellular” fluid compartment of the body includes which of the following?
    A. Interstitial, transcellular and connective tissue fluids
    B. Vascular, connective tissue and interstitial fluids
    C. Intracellular and transcellular fluid
    D. Vascular and connective tissue fluid

Answer 22

Answer is B: Extracellular must include the blood (vascular) and the fluid between cells (interstitial).

Question 23

23. Fluid and electrolyte balance in the body is maintained by which of the following?
    A. The hormone aldosteron
    B. Keeping accurate account of the patient’s fluid balance chart
    C. The nephron of the kidney
    D. The hypothalamus of the brain

Answer 23

Answer is C: The nephron is the functional unit of the kidney that does this job.

Question 24

24. Which general description of the components of a solution is correct?
    A. Solvent and solute
    B. Solvent and liquid
    C. Solute and solder
    D. Liquid and solid

Answer 24

Answer is A: The solvent dissolves (e.g. water); the solute (e.g. salt) is dissolved

Question 25

25. Which term below is NOT suitable to describe the concentration of a solution? A. 5 g/L B. 5% C. 2 Molar D. 0.5 mole

Answer 25

Answer is D: This states an amount of substance only, without reference to the volume of solvent involved

Question 26

26. Given that the healthy range of sodium ion concentration in the blood is 137–145 mmol/L, if the measured concentration of a blood sample was 130 mmol/L, what would the condition be called? A. Hyperkalaemia B. Hypokalaemia C. Hypernatremia D. Hyponatremia

Answer 26

Answer is D: Natrium is sodium. As 130 is less than 137, the prefix “hypo-” is the correct one.

Question 27

27. Extracellular fluid includes which of the following liquids? A. Blood plasma B. Blood plasma and interstitial fluid C. Blood plasma and interstitial fluid and connective tissue fluid D. Blood plasma and interstitial fluid and connective tissue fluid and liquid inside cells

Answer 27

Answer is C: This choice includes more than choices A and B. D is wrong as liquid inside cells is not extracellular

Question 28

28. What can be said about a solution that conducts electricity? A. The solute is a polar molecule. B. The solvent is a non-polar liquid C. The solution contains dissolved ions. D. The solution contains dissolved molecules

Answer 28

Answer is C: Dissolved ions must be present for electrical conduction to occur.

Question 29

29. Which of the body’s fluid compartments does the vascular compartment form part of? A. Interstitial fluid B. Extracellular fluid C. Intracellular fluid D. Transcellular fluid

Answer 29

Answer is B: Vascular = blood which is almost synonymous with extracellular.

Question 30

30. To what condition does the term “hypokalaemia” refer to? A. Too little phosphorus in the blood B. Too much sodium in the blood C. Too little potassium in the blood D. Too little sodium in the blood

Answer 30

Answer is C: Hypo- refers to too little and kalium is the Latin word for potassium.

Question 31

31. Which of the following is correct for intracellular fluid (ICF) and extracellular fluid (ECF)? A. The ECF is part of the ICF. B. The majority of the body’s water is in the ECF. C. The ICF contains more sodium than the ECF. D. The ICF contains more potassium than the ECF.

Answer 31

Answer is D: There is more K within cells than outside cells (the reverse is true for sodium). Most body water is inside the cells.

Question 32

32. A 1 L IV bag contains 0.18% sodium chloride and 4% glucose. What mass of solutes would be dissolved in 100 ml of the solution? A. 0.18 g of sodium chloride and 4 g of glucose B. 1.8 g of sodium chloride and 4 g of glucose C. 1.8 g of sodium chloride and 40 g of glucose D. 18 g of sodium chloride and 40 g of glucose

Answer 32

Answer is A: 0.18% sodium chloride and 4% glucose means 0.18 g of sodium chloride per 100 ml and 4 g of glucose per 100 ml.

Question 33

33. In the context of fluid (water) balance, the body is said to have “two compartments”. What are they? A. The vascular and the interstitial compartments B. The intracellular and the interstitial compartments C. The lymph and the vascular compartments D. The extracellular and the intracellular compartments

Answer 33

Answer is D: Outside the cells and inside the cells include everything.

Question 34

34. What is an insufficient concentration of potassium in the blood known as? A. Hypokalaemia B. Hyponatremia C. Hypopotassaemia D. Hypocalcaemia

Answer 34

Answer is A: The Latin word for potassium is kalium. The prefix “hypo-” refers to too little. Arguably, choice C is not wrong, but this expression is not used.

Question 35

35. If a solution is shown to be able to conduct electricity, then what is true? A. The solution is free of impurities. B. The solution contains a dissolved electrolyte. C. The solution contains dissolved molecules. D. The solution is an aqueous solution.

Answer 35

Answer is B: A dissolved electrolyte will ensure that ions are in solution and the solution will conduct electricity as these ions are free to move through the solution.

Question 36

36. How many grams of sodium chloride are there in a 1 L bag of 4% glucose and 0.18% sodium chloride solution? A. 0.18 B. 1.8 C. 18 D. 41.8

Answer 36

Answer is B: 0.18% = 0.18 g per 100 ml, so in 1000 ml, there would be 10×0.18 = 1.8 g.

Question 37

37. In the vascular compartment of the body, what is the solvent? A. Blood B. Plasma C. Serum D. Water

Answer 37

Answer is D: All these things are in the vascular compartment, but water is the solvent.

Question 38

38. The extracellular fluid compartment consists of which of the following? A. Vascular and transcellular B. Interstitial, vascular and connective tissue fluid C. Intracellular and transcellular D. Transcellular, intracellular and connective tissue fluid

Answer 38

Answer is B: Vascular and interstitial liquids must be included.

Question 39

39. Electrolyte balance is achieved largely by: A. The kidneys and aldosterone B. Drinking sufficient water C. Antidiuretic hormone and isotonic fluids D. Ensuring that daily water intake is the same as daily water output

Answer 39

Answer is A: The kidneys have the ability to reabsorb and secrete ions and water as required. Aldosterone causes the kidney tubules to reabsorb sodium ions while promoting the secretion of potassium ions.

Question 40

40. What may hyponatremia be described as? A. Insufficient potassium in the blood B. Insufficient iron in the blood C. Insufficient sodium in the blood D. Excess sodium in the blood

Answer 40

Answer is C: The prefix “hypo-” refers to too little, and natrium is a Latin word that means sodium.

Question 41

41. Which of the following ways of expressing a solution’s concentration is written as a number without units? A. % concentration B. Molarity C. Osmotic pressure D. Specific gravity

Answer 41

Answer is D: Specific gravity of a solution is the ratio of the density of the solution to the density of water (which is 1.0). Consequently the density units “cancel out”.

Question 42

42. A solution of 5% glucose is infused over a period of 3 h. If 250 ml of solution was used, how many grams of glucose were infused? A. 5 g B. 12.5 g C. 15.0 g D. 50 g

Answer 42

Answer is B: 5% glucose means 5 g per 100 ml of solution. 250 mL was used, there- fore 2.5×5 = 12.5 g

Question 43

43. A solution is prepared by dissolving 10 g of glucose in 250 ml of water. What will be the concentration of this solution expressed as a percentage? A. 4 B. 6 C. 25 D. 40

Answer 43

Answer is A: % concentration states how many grams of solute are in 100 ml of solution. 10 g per 250 ml is the same as 10÷2.5 per 100 ml. This is 4%

Question 44

44. What quantity is used to express the concentration of dissolved oxygen in blood? A. Partial pressure B. Osmotic pressure C. Molarity D. Osmolarity

Answer 44

45. If the label on a bottle of beer states that it contains 5.9% alcohol, how much alcohol does the bottle contain? A. 5.9 g per 100 ml B. 0.9 g per 100 ml C. 5.9 g D. 5.0 g per 100 ml Answer is A: 5.9% means that there is 5.9 g of alcohol per 100 ml of beer. “Percent” means “in a 100”.

Question 45

46. A healthy concentration of cholesterol in the blood is deemed to be less than 5.5 mmol/L. Which value below is greater than this value? A. 0.0045 mol/L B. 0.005 mol/L C. 5000 μmol/L D. 6000 μmol/L

Answer 45

Answer us D: 6000 μmol/L is the same as 6.0 mmol/L. All other values are less than 5.5 mmol/L.

Question 46

47. Which of the following refers to the concentration of a solution? A. Systolic pressure B. Osmotic pressure of blood C. Diastolic pressure D. Partial pressure of O2 in blood

Answer 46

Answer is B: Although “pressure” appears in this term, it refers to the solution con- centration when expressed in units of pressure. Choice D also refers to a concentration but of only one of the dissolved species.

Question 47

48. Which of the following is NOT one of the body’s fluid compartments? A. The interstitial compartment B. The intracellular compartment C. The gastrointestinal compartment D. The extracellular compartment

Answer 47

Answer is C: The contents of the gut are not regarded as one of the body’s fluid compartments.

Question 48

48. Which of the following is NOT one of the body’s fluid compartments? A. The interstitial compartment B. The intracellular compartment C. The gastrointestinal compartment D. The extracellular compartment

Answer 48

Answer is A: The intracellular compartment contains about 27 of the body’s 42 L or so of solution. The next largest is the extracellular with about 15 L. The other two are subsets of the extracellular compartment.