GOB Chemistry Study Notes: Acids, Bases, Gas Laws, and Solution Chemistry

Acids, Bases, and Solution Chemistry

Strong Acids and Bases

Understanding strong acids and bases is essential for predicting chemical reactivity and solution properties. Strong acids and bases dissociate completely in water, making them important in many chemical reactions.

• Common Strong Acids: HCl, HBr, HI, HNO3, H2SO4, HClO4

• Common Strong Bases: NaOH, KOH, LiOH, Ca(OH)2

Definition: A strong acid or base is one that completely ionizes in aqueous solution.

Example: HCl in water: $\mathrm{HCl} \rightarrow \mathrm{H^+} + \mathrm{Cl^-}$

States of Matter and Gas Laws

Gas Laws

Gas laws describe the relationships between pressure, volume, temperature, and amount of gas. They are fundamental for understanding the behavior of gases in chemical and biological systems.

• Boyle's Law: At constant temperature, the pressure and volume of a gas are inversely related.

• Charles's Law: At constant pressure, the volume of a gas is directly proportional to its temperature (in Kelvin).

• Combined Gas Law: Combines Boyle's and Charles's laws to relate pressure, volume, and temperature.

Formulas:

• Boyle's Law: $P_1 V_1 = P_2 V_2$

• Charles's Law: $\frac{V_1}{T_1} = \frac{V_2}{T_2}$

• Combined Gas Law: $\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$

Temperature Conversion: Kelvin = Celsius + 273

Pressure Units: 1 atm = 760 mmHg = 14.7 psi

Solution Chemistry

Concentration Units

Concentration expresses the amount of solute in a given amount of solution. Several units are used in chemistry to describe concentration.

• Molarity (M): Moles of solute per liter of solution.

• Percent Mass/Mass (% w/w): $\frac{\text{mass of solute}}{\text{mass of solution}} \times 100\%$

• Percent Mass/Volume (% w/v): $\frac{\text{mass of solute}}{\text{volume of solution in mL}} \times 100\%$

• Percent Volume/Volume (% v/v): $\frac{\text{volume of solute}}{\text{volume of solution}} \times 100\%$

• Parts per Million (ppm): $\frac{\text{mass of solute}}{\text{mass of solution}} \times 10^6$

Example: To prepare a 0.9% (w/v) saline solution, dissolve 0.9 g NaCl in enough water to make 100 mL solution.

Common Polyatomic Ions

Polyatomic ions are ions composed of two or more atoms covalently bonded, acting as a single charged unit in chemical reactions.

Ion Name	Formula
Hydroxide	OH-
Acetate	CH3COO-
Cyanide	CN-
Nitrate	NO3-
Sulfate	SO42-
Sulfite	SO32-
Carbonate	CO32-
Phosphate	PO43-
Ammonium	NH4+

Application: Polyatomic ions are commonly found in biological molecules and industrial chemicals.