Chemistry Practice: Concepts, Reactions, and Energy

Flashcards covering general chemistry foundations, including atomic structure, nomenclature, stoichiometry, thermodynamics, gas laws, and acid-base chemistry.

Density

An example of a physical property characteristic of matter.

Sand in water

An example of a heterogeneous mixture.

$$0.003040$$

A numerical value containing $4$ significant figures.

$$0.0072$$

The standard notation representation of the value $7.2 \times 10^{-3}$.

milli

The metric prefix that represents the factor $10^{-3}$.

Neutron

The subatomic particle that possesses no electrical charge.

Mass number

The sum of protons and neutrons in an atom.

Magnesium ($Mg$)

An element classified as an alkaline earth metal.

Electronegativity trend

Increases as one moves right across a period on the periodic table.

p subshell

A subshell that can hold a maximum of $6$ electrons.

Ionic compound

A chemical compound such as $NaBr$, characterized by ionic bonding.

Magnesium chloride

A compound with the chemical formula $MgCl_2$.

Iron (III) oxide

The chemical name for the compound with the formula $Fe_2O_3$.

Sulfate ($SO_4^{2-}$)

An example of a polyatomic ion.

Calcium nitrate

A chemical compound with the formula $Ca(NO_3)_2$.

$C-F$ bond

An example of a bond that is considered highly polar.

Carbon dioxide ($CO_2$)

A molecule that is nonpolar despite having polar bonds.

Trigonal pyramidal

The molecular shape of an ammonia ($NH_3$) molecule.

Hydrogen bonding

A specific type of intermolecular force that occurs in molecules such as $NH_3$.

Oxygen valence electrons

The number of valence electrons in oxygen, which is $6$.

Decomposition reaction

A reaction type following the general form $AB \rightarrow A + B$.

Balanced water equation

$2H_2 + 1O_2 \rightarrow 2H_2O$.

Avogadro’s number

The constant equal to $6.02 \times 10^{23}$.

Molar mass of $H_2O$

The mass of one mole of water, approximately $18\,g\,mol^{-1}$.

$$1\,mol$$

The number of moles contained in $44\,g$ of $CO_2$.

Percent yield formula

$\frac{\text{actual}}{\text{theoretical}} \times 100$.

Limiting reagent

The reactant that determines the theoretical yield of a chemical reaction.

Single replacement reaction

A reaction type following the general form $A + BC \rightarrow AC + B$.

Spectator ions

Ions that are removed when writing a net ionic equation.

Exothermic reactions

Chemical reactions that release heat into the surroundings.

Endothermic reactions

Reactions characterized by a positive change in enthalpy ($\Delta H$).

Catalyst

A substance that increases the reaction rate by lowering the activation energy ($E_a$).

$$K_{eq} > 1$$

An equilibrium constant value indicating that the reaction favors the products.

Le Chatelier’s Principle

The principle stating that a system at equilibrium will counter any applied stress.

Bond breaking

A process that always absorbs energy.

Activation energy

Represented by the energy hill in a reaction coordinate diagram.

Standard Molar Volume

At STP, $1\,mol$ of gas occupies $22.4\,dm^3$.

Kelvin

The temperature scale that must be used in gas law calculations.

Boyle’s law

The gas law described by an inverse relationship between pressure and volume.

Dalton’s law

The law of partial pressures where $P_{total} = P_A + P_B + P_C$.

Vaporization

The phase change occurring when a liquid becomes a gas.

Deposition

The phase change occurring when a gas turns directly into a solid.

“Like dissolves like”

A rule of solubility meaning polar substances dissolve polar substances.

Molarity

A unit of concentration measured in $mol\,dm^{-3}$.

Dilution formula

The equation represented by $M_1V_1 = M_2V_2$.

Hypertonic solution

A solution that causes blood cells to shrink.

Arrhenius acid

A substance that produces $H^+$ ions in solution.

Bronsted-Lowry base

A substance that acts as a proton ($H^+$) acceptor.

pH formula

The mathematical expression $pH = -\log(H_3O^+)$.

Buffer solution

A solution that resists rapid changes in pH.

An example of a physical property characteristic of matter.

Density

An example of a heterogeneous mixture.

Sand in water

A numerical value containing $4$ significant figures.

$$0.003040$$

The standard notation representation of the value $7.2 \times 10^{-3}$.

$$0.0072$$

The metric prefix that represents the factor $10^{-3}$.

milli

The subatomic particle that possesses no electrical charge.

Neutron

The sum of protons and neutrons in an atom.

Mass number

An element classified as an alkaline earth metal.

Magnesium ($Mg$)

Increases as one moves right across a period on the periodic table.

Electronegativity trend

A subshell that can hold a maximum of $6$ electrons.

p subshell

A chemical compound such as $NaBr$, characterized by ionic bonding.

Ionic compound

A compound with the chemical formula $MgCl_2$.

Magnesium chloride

The chemical name for the compound with the formula $Fe_2O_3$.

Iron (III) oxide

An example of a polyatomic ion.

Sulfate ($SO_4^{2-}$)

A chemical compound with the formula $Ca(NO_3)_2$.

Calcium nitrate

An example of a bond that is considered highly polar.

$C-F$ bond

A molecule that is nonpolar despite having polar bonds.

Carbon dioxide ($CO_2$)

The molecular shape of an ammonia ($NH_3$) molecule.

Trigonal pyramidal

A specific type of intermolecular force that occurs in molecules such as $NH_3$.

Hydrogen bonding

The number of valence electrons in oxygen, which is $6$.

Oxygen valence electrons

A reaction type following the general form $AB \rightarrow A + B$.

Decomposition reaction

$2H_2 + 1O_2 \rightarrow 2H_2O$.

Balanced water equation

The constant equal to $6.02 \times 10^{23}$.

Avogadro’s number

The mass of one mole of water, approximately $18\,g\,mol^{-1}$.

Molar mass of $H_2O$

The number of moles contained in $44\,g$ of $CO_2$.

$$1\,mol$$

$\frac{\text{actual}}{\text{theoretical}} \times 100$.

Percent yield formula

The reactant that determines the theoretical yield of a chemical reaction.

Limiting reagent

A reaction type following the general form $A + BC \rightarrow AC + B$.

Single replacement reaction

Ions that are removed when writing a net ionic equation.

Spectator ions

Chemical reactions that release heat into the surroundings.

Exothermic reactions

Reactions characterized by a positive change in enthalpy ($\Delta H$).

Endothermic reactions

A substance that increases the reaction rate by lowering the activation energy ($E_a$).

Catalyst

An equilibrium constant value indicating that the reaction favors the products.

K_{eq} > 1

The principle stating that a system at equilibrium will counter any applied stress.

Le Chatelier’s Principle

A process that always absorbs energy.

Bond breaking

Represented by the energy hill in a reaction coordinate diagram.

Activation energy

At STP, $1\,mol$ of gas occupies $22.4\,dm^3$.

Standard Molar Volume

The temperature scale that must be used in gas law calculations.

Kelvin

The gas law described by an inverse relationship between pressure and volume.

Boyle’s law

The law of partial pressures where $P_{total} = P_A + P_B + P_C$.

Dalton’s law

The phase change occurring when a liquid becomes a gas.

Vaporization

The phase change occurring when a gas turns directly into a solid.

Deposition

A rule of solubility meaning polar substances dissolve polar substances.

“Like dissolves like”

A unit of concentration measured in $mol\,dm^{-3}$.

Molarity

The equation represented by $M_1V_1 = M_2V_2$.

Dilution formula

A solution that causes blood cells to shrink.

Hypertonic solution

A substance that produces $H^+$ ions in solution.

Arrhenius acid

A substance that acts as a proton ($H^+$) acceptor.

Bronsted-Lowry base

The mathematical expression $pH = -\log(H_3O^+)$.

pH formula

A solution that resists rapid changes in pH.

Buffer solution