Unit 4 - Chemical attractions

polarity

Uneven distribution of particles in a molecule, leading to hydrogen bonding.

law of conservation of mass

The principle stating that starting materials equal ending materials.

chemical equation

Representation of a chemical reaction with reactants and products separated by plus signs and yields.

mole

The amount of substance containing 6.022 × 10²³ particles.

solution

A homogeneous mixture consisting of solute and solvent.

solubility

The ability of a solute to dissolve in a solvent.

concentration

The amount of substance within a defined space.

ionic compounds

Compounds held together by strong attractive forces, resulting in high melting points.

molecular compounds

Compounds with weaker attractive forces leading to lower melting points.

electronegativity

The tendency of an atom to pull electrons towards itself.

nonpolar covalent bond

A bond where two atoms of the same element share electrons evenly.

polar molecule

A molecule with a partial negative charge at one end and a partial positive charge at the other.

dipole

A molecule with two poles due to uneven charge distribution.

hydrogen bonding

Strong attractions between molecules that contain hydrogen bonded to highly electronegative atoms.

saturated solution

A solution that contains the maximum amount of dissolved solute.

strong electrolyte

A substance that conducts electricity well when dissolved in solution.

weak electrolyte

A substance that conducts electricity poorly in solution.

osmotic pressure

The external pressure applied to stop osmosis, dependent on solute concentration.

isotonic solution

A solution where the concentration of solute is equal inside and outside of a cell.

hypotonic solution

A solution where the concentration of solute is lower outside the cell, causing it to swell.

hypertonic solution

A solution where the concentration of solute is higher outside the cell, causing it to shrink.

colloids

Mixtures where smaller particles are dispersed in a continuous medium, appearing homogeneous.

dissociation

The process where polar water molecules surround and separate ions in a solution.

precipitation

The process where a combination of ions forms an insoluble compound.

vapor pressure

Pressure exerted by a vapor in equilibrium with its liquid or solid form.

colligative properties

Properties of solutions that depend on the concentration of solute particles, not their identity.

What is molarity?

A measure of the concentration of a solute in a solution, expressed as moles of solute per liter of solution.

How is molarity calculated?

Molarity (M) is calculated using the formula: M = moles of solute / liters of solution.

What is the unit of molarity?

The unit of molarity is moles per liter (mol/L).

What is a 1 M solution?

A 1 M solution contains 1 mole of solute in 1 liter of solution.

What is the difference between molarity and molality?

Molarity refers to moles of solute per liter of solution, while molality refers to moles of solute per kilogram of solvent.

How does temperature affect molarity?

Molarity can change with temperature because it depends on the volume of the solution, which can expand or contract with temperature changes.

What is the formula for dilution?

The dilution formula is: M₁V₁ = M₂V₂, where M is molarity and V is volume.

What is a concentrated solution?

A concentrated solution contains a large amount of solute relative to the amount of solvent.

What is Coulomb's Law?

Coulomb's Law describes the force between two charged particles.

What is the formula for Coulomb's Law?

The formula is F = k * |q1 * q2| / r², where F is the force, k is Coulomb's constant, q1 and q2 are the charges, and r is the distance between them.

What do the variables in Coulomb's Law represent?

F = force between the charges, k = Coulomb's constant (8.99 × 10⁹ N m²/C²), q1 and q2 = magnitudes of the charges, r = distance between the charges.

What is Coulomb's constant?

Coulomb's constant (k) is approximately 8.99 × 10⁹ N m²/C².

How does distance affect the force in Coulomb's Law?

The force is inversely proportional to the square of the distance (r²) between the charges.

What happens to the force if the distance is doubled?

If the distance is doubled, the force becomes one-fourth as strong.

What is the direction of the force in Coulomb's Law?

The force is directed along the line connecting the two charges; it is attractive for opposite charges and repulsive for like charges.

What units are used in Coulomb's Law?

Charges are measured in coulombs (C), force is measured in newtons (N), and distance is measured in meters (m).

What is water disinfection?

The process of removing or killing harmful microorganisms in water.

What methods are commonly used for water disinfection?

Chlorination, UV radiation, ozonation, and filtration are common methods.

What is chlorination in water treatment?

The addition of chlorine to water to eliminate bacteria and other pathogens.

What is the purpose of water filtration?

To remove suspended particles, sediment, and contaminants from water.

What is sedimentation in water treatment?

The process of allowing large particles to settle at the bottom of a container before filtration.

What is the role of water chemists in water quality?

They analyze and test water samples to ensure safety and compliance with health standards.