Electrolytes and pH Concepts in Chemistry

Study Notes

Milliequivalent is a unit used to express electrolyte concentrations, highlighting the equivalence of ions involved.
High resistivity in substances indicates a strong ability to resist the flow of electric current, while low resistivity allows free electrical movement.
Electrolytes consist of cations (e.g., sodium, potassium, magnesium, calcium) and anions (e.g., chloride, bicarbonate, phosphate).
Resistivity of water correlates with purity: higher impurity results in increased resistivity, obstructing current flow.

Normal arterial plasma pH ranges from 7.35 to 7.45, influencing metabolic activities and tissue physiology.
pH indicates acidity or basicity; it inversely correlates with hydrogen ion concentration (lower pH = higher HIC).
Buffers help maintain stable pH levels by minimizing hydrogen ion concentration changes.

Solvent: typically water, known as a universal solvent.
Solute: any substance dissolved within the solvent.
Molarity (M) quantifies solute concentration, defined as moles per liter of solution.
Percent solutions express solute concentration in terms of parts per 100, with three main types: weight/weight, volume/weight, and weight/volume.

Molar solution defined by gram molecular weight dissolved to attain a final volume of 1L.
Grams of solute derived from the formula: % w/v x mL of solution / 100.
Stepwise problem-solving approach includes identifying the given, the unknown, and the appropriate formula.

Normality measures the gram equivalent weight of solute per liter of solution.
Equivalent weight calculated by dividing molecular weight by valence (number of electrons exchanged).
Conversion formulas enable transition between normality and molarity.

Molality measures the amount of solute per 1 kg of solvent, represented in mol/kg.
Colligative properties affect solvent behavior, influencing vapor pressure, freezing point, boiling point, and osmotic pressure.

Vapor Pressure: equilibrium point between liquid and vapor states.
Freezing Point: defined as 0°C for pure water.
Boiling Point: temperature at which vapor pressure equals 1 atmosphere.
Osmotic Pressure: pressure causing solvent movement through a semipermeable membrane.

Conductivity measures how well a solution permits electric current flow, with units in OHM-1 (Mho).
Conductivity can be affected by ion charge within the solution, impacting resistance to electrical passage.

Solutions can be categorized as dilute, concentrated, saturated, or supersaturated based on solute quantity.
Supersaturated solutions are thermodynamically unstable; excess solute can be crystallized by adding crystals or mechanical agitation.
Resisting measures, referred to as resistivity, describe how much a substance can hinder electric current passage.