Water: The Universal Solvent
- Water is a very versatile solvent because polar molecules are attracted to other polar molecules + its molecules form HB (adhesive)
- (+) and (-) attraction
- Why are ionic compounds soluble in water?
- When ionic compounds are dissolved, the dipole of the water interacts with the charged ions and causes them to separate
- The strong forces present among the positive and negative ions of the solid are replaced by stronger ion-dipole interactions → the interaction is energetically favorable
- Hydration: “positive ends” of the water molecules are attracted to the negatively charged anions and that the “negative ends” are attracted to the positively charged cations
- When ionic substances (salts) dissolve in water, they break up into the individual cations and anions.
The Nature of Aqueous Solutions: Strong and Weak Electrolytes
- Electrical conductivity: its ability to conduct an electric current
- Electrolyte: compound that conducts an electric current when dissolved in water or melted
- Has charged particles
Strong Electrolytes
- Strong electrolytes: substances that completely ionizes when they are dissolved in water (NaCl)
- All ionic compounds and strong acids are strong electrolytes
- Aqueous solutions with them conduct an electric current very efficiently
Weak Electrolytes
- Weak electrolytes: only a few ions produced when dissolved in water (ex: acetic acid)
- Solutions with them conduct only a small current
- Weak acid (NH4+ ammonium ion)/base (NH3 ammonia) = weak electrolyte
Nonelectrolytes
- Nonelectrolyte: substances that dissolves in water but do not produce any ions (ex: sugar, ethanol) → instead entire molecules dispersed in the water → solution does not conduct an electric current