Question

In Lab Exercise 8 you measured the electrical resistance of a number of solutions in order to determine whether a particular substance is ionic or covalent. Suppose you measure the resistance of a solution of NaCl, and the resistance was 2600 ohms. What resistance would you expect to measure for a solution of CH₃OH dissolved in water?

Select one:

a. 1200 ohms

b. More than 10,000 ohms

c. 1800 ohms

d. 2600 ohms

e. 2700 ohms

Answer 1

NaCl is an ionic compound and hence a strong electrolyte which means that it fully dissociates into ions Na⁺ and Cl^-. A substance which can dissociate into ions in water is a very good conductor and has a low resistance.

CH₃OH on the other hand is a very weak acid and bonds in it are covalent in nature which do not break easily into water. Thus, it is a very poor conductor of electricity and its resistance will be much higher than that of NaCl.

Thus, the appropriate answer will be b. More than 10000 ohms