What would happen with non-electrolytes?
3 marks · EasyA student investigates the conductivity of three white solids: sodium chloride, glucose, and wax. She sets up the following experiment:
Sodium chloride does not conduct electricity as a solid, but the bulb lights up when it is dissolved in water. What does this indicate about sodium chloride?
Glucose does not conduct electricity, whether solid or dissolved in water. What type of substance is glucose?
Wax does not conduct electricity as a solid or when melted. What does this suggest about wax?
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) It is ionic. · must show identifies sodium chloride as ionic
(b) It is a non-electrolyte (covalent). · must show identifies glucose as non-electrolyte/covalent
(c) Wax is a non-electrolyte (does not contain ions). · must show identifies wax as non-electrolyte
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Identifies sodium chloride as ionic based on conductivity in solution only.
B1 (b) · 1 mark · Identifies glucose as a non-electrolyte or covalent compound (never conducts).
B1 (c) · 1 mark · Identifies wax as a non-electrolyte (never conducts).
Worked solution
a) Sodium chloride conducts only when dissolved, so it must be ionic.
b) Glucose never conducts, so it is a non-electrolyte (covalent).
c) Wax never conducts, even when melted, so it is a non-electrolyte.