Solutions are sometimes grouped according to their ability to conduct electricity. Substances whose solutions conduct electricity are called electrolytes and those that do not conduct electricity are called nonelectrolytes. Also electrolytes can be strong or weak. Under strong electrolytes we have NaCl and CaCl2 which are ionic compounds, HCI, HNO3, HBr and H2SO4 are under acids and NaOH, KOH, and LiOH are under bases. Weak electrolytes are ionic compounds and slightly soluble such as CH3COOH, under acids we have HF, H2CO3, H2SO3, and NH3.While nonelectrolytes are nonpolar covalent compounds such as O2 and H2O, and under acids we have CS2, CCI4, C6H6, and C2H12O6. Figure 9.17 Electrical Conductivity of Solution
(a) Water does not conduct electricity.
(b) Sodium Chloride solution conducts electricity and the bulb glows brightly. (c) Sugar solutions do not conduct electricity.
(d) Acetic acid is a weak electrolyte does not efficiently conduct electricity.
Bulb doesBulb glows Bulb does Bulb glows not light brightly not light dimly
Pure water0.10 NaCl (aq)0.10 M sugar (aq) 0.10 M CH2COOH (aq) (a) (b) (c) (d)
Figure 9.17, shows simple apparatus that determines the relative conductivities of pure water and solutions. Two metal electrodes are connected to a battery and a light bulb. When the electrodes are immersed in the solution, the light bulb will glow only if circuit is complete so that electricity flows from one electrode to the other through the solution. The more ions a solutions has, the greater conductivity and the greater conductivity and the brighter glow of the light bulb is.