Chemistry and Physics Lecture Review

These flashcards cover the key concepts discussed in the Chemistry, Electric Potential, and Fluids lectures, including definitions, laws, and relationships.

What did Volta discover about electricity?

Electricity could be created if dissimilar metals were connected by a conductive solution called an electrolyte.

What is the function of a battery?

A battery transforms chemical energy into electrical energy through dissolving terminals.

What is Electric Current?

The rate of flow of charge through a conductor, measured in amperes (A), where 1 A = 1 C/s.

What is a complete circuit?

A circuit where current can flow continuously.

According to experiments, what is the relationship between current in a wire and potential difference?

Current is proportional to the potential difference between its ends.

What is resistance?

The ratio of voltage to current (V/I).

What are nonohmic materials?

Materials that do not follow Ohm’s law.

What are some clarifications about batteries and resistance?

Batteries maintain a constant potential difference, while resistance is a property of a material or device.

How is the resistance of a wire determined?

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area.

What is resistivity?

A material's characteristic, increasing with temperature

What is electric power?

The energy transformed by a device per unit time, P = IV.

What do electric companies measure on your bill?

The power consumption multiplied by the time; measured in kilowatt-hours (kWh).

What are fuses or circuit breakers for?

Devices that disconnect a circuit when the current exceeds a certain value, preventing fires.

What is direct current (DC)?

Current that flows steadily in one direction.

What is alternating current (AC)?

Current that varies sinusoidally.

What is root-mean-square (rms) value?

The effective value of the current or voltage that would result in the same energy dissipation as a steady DC value.

What is an atom?

The smallest particle of an element with that element's properties that can react chemically.

What is a molecule?

Two or more atoms connected by chemical bonds.

What are elements?

Composed of one type of element (e.g., gold (Au), phosphorus (P), oxygen (O)).

What are compounds?

Composed of two or more types of elements chemically bonded (e.g., H2O, C6H12O6, AgCl).

What is a mixture?

Two or more types of matter that can be present in varying amounts and separated by physical changes.

What is a homogenous mixture?

Exhibits a uniform composition.

What is a heterogeneous mixture?

Has a composition that varies from point to point.

What is a physical property?

A characteristic of matter not associated with a change in its chemical composition.

What is a physical change?

A change in the state or properties of matter without changing the chemical composition.

What is a chemical property?

The change of one type of matter into another, or the inability to change.

What is the Law of conservation of matter?

There is no detectable change in the total quantity of matter present when matter converts from one type to another

What is electric potential related to potential energy?

Electric potential is potential energy per unit charge: V = U/q.

How is the potential difference between two points measured?

With the potential difference between two points = VB – VA = -WAB/q.

Give the equation of a point charge.

The potential of a point charge is V = kQ/r.

Define pressure.

The force exerted on a given area, measured in Pascals (Pa).

What is Amonton’s or Gay-Lussac’s Law?

For a constant gas amount (n) and volume (V), the gas pressure (P) is directly proportional to the temperature.

What is Charles’ Law?

At constant pressure (P) and gas amount (n), the volume (V) is directly proportional to the temperature in Kelvin.

What is Boyle’s Law?

At constant temperature (T) and gas amount (n), the volume (V) is inversely proportional to the pressure (P).

What is Avogadro’s Law?

The volume (V) is directly proportional to its amount (n) or moles of gas.

What is the Ideal Gas Law?

PV = nRT

What is partial pressure?

The pressure exerted by each individual gas in a mixture is called its partial pressure.

What is Dalton’s Law of partial pressure?

PT = PA + PB + PC + …

How is partial pressure of a gas expressed by its mol fraction?

PA = XAPT

What is the relationship between volumes of two gases in a reaction?

The volume ratio of any two gases in a reaction at constant temperature and pressure is the same as the stoichiometric ratio in the balanced chemical equation.

What are intermolecular forces (IMFs)?

The various forces of attraction that exist between the atoms and molecules of a substance, due to electrostatic phenomena.

What are dispersion forces?

Constant motion of electrons in molecules and atoms result in instantaneous dipoles. An instantaneous dipole in one molecule can distort the electrons in neighboring atoms, producing an induced dipole.

What are dipole-dipole attractions?

Exhibited by polar molecules with permanent dipoles; stronger than dispersion forces.

What is hydrogen bonding?

An unusually strong type of dipole-dipole attraction between an H atom covalently bonded to N, O, or F.

What is a precipitation reaction?

Dissolved substances react to form one (or more) solid products.

What is an acid-base reaction?

A hydrogen ion (H+) is transferred from one chemical species to another.

What is an acid?

A substance that dissolves in water to yield hydronium ions (H3O+).

What is a base?

A substance that dissolves in water to yield hydroxide ions (OH−).

What is a neutralization reaction?

The reactants are an acid and a base, and the products are often a salt and water.

What are Oxidation-reduction (redox) reactions?

One or more elements involved undergo a change in their oxidation number.

What is reduction?

When one or more elements gain electrons in a Redox reaction

What is oxidation?

When one or more elements lose electrons in a Redox reaction.

What is Oxidation State?

Using the numbers as calculated by assigning the element with a charge it would possess if the compound was ionic, to determine type of reaction

What is a reaction’s stoichiometry?

The quantitative relationships between the amounts of reactants and products involved in a chemical reaction.

What is the theoretical yield?

The amount of product that may be produced by a reaction, as calculated per stoichiometry.

What is the actual yield?

The amount of product obtained.

What is Molarity?

M(olarity) = mol solute/ L solution

Pressure tends to be low

What happens with fluids as velocity is high?