4.2 Solutions Flashcards
- 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 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.
- 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 is B: 0.1 mol = 1/10 of 58.5 g = 5.85 g
- 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 is D: 0.9% means 0.9 g per 100 ml of solution = 9 g per 1000 ml (i.e. per litre)
- 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 is C: 0.9% means 0.9 g per 100 ml of solution = 9 g per 1000 ml (i.e. per litre)
- 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 is C: 80 g per 1000 ml = 8 g per 100 ml = 8%
- 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 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%
- 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 is C: This is the definition of an electrolyte.
- 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 is A: 0.18% means 0.18 g per 100 ml of solution
- 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 is C: Glucose will dissolve in water, but being a molecular compound, it does not produce ions.
- 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 is B: 5% = 5% = 5 per hundred = 5 g per 100 ml of solution.
- 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 is B: This is a definition of electrolyte.
- 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 is A: 0.9% = 0.9% = 0.9 per hundred = 0.9 g per 100 ml of solution.
- 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 is C: Haemoglobin is an uncharged protein found within red blood cells.
- 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 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
- 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 is A: Kalaemia refers to potassium. “Hyper-” refers to more or an excess.
- 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 is C: 5% means 5 g per 100 ml. So in 300 ml there would be 3×5 g = 15 g infused.
- 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 is A: 5 g per 250 ml = 20 g per 1000 ml (multiply by 4) = 2 g per 100 ml = 2%.
- 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 is C: Kalium means potassium; the prefix “hypo-” means a lack or decrease in.
- 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 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