Unit 3

Significant Digits (sig-digs)

Digits in a number that contribute to the precision.

What do leading zeros indicate in significant digits?

Leading zeros (any 0 before a significant number) do not matter.

What are captive zeros in terms of significant digits?

Captive zeros are any 0s that are in between significant numbers and matter.

What are trailing zeros?

Trailing zeros are any 0s that trail a significant number but are around a decimal point, and they matter.

What defines an exact number in significant digits?

An exact number has an infinite amount of significant digits and is either counted or has a defined quantity.

Formula for % mass

%mass = mass solute/mass solution x 100%.

What signifies a homogenous mixture?

A homogenous mixture is a mixture where different components are not visible and the composition is constant throughout.

What is a solute?

A solute is the substance that dissolves within the solvent.

What are electrolytes?

Electrolytes are ionic compounds that, when dissolved in water, conduct electricity.

What happens during the process of dissolving?

The intermolecular bonds between solute particles break apart, while some intermolecular bonds between solvent particles must also break.

What is solubility?

The solubility of a solute is the amount of solute that can dissolve in a given quantity of solvent at a specific temperature.

What is the characteristic of a saturated solution?

A saturated solution contains the maximum amount of dissolved solute at a given temperature.

Describe a supersaturated solution.

A supersaturated solution contains more dissolved solute than its solubility value at a given temperature.

What does the pH scale measure?

The pH scale measures the concentration of hydronium ions (H3O+) in a solution.

What is the definition of a strong acid?

A strong acid completely ionizes in solution.

What does the Arrhenius Theory state regarding acids and bases?

Acids are substances that ionize to form hydrogen ions, while bases are substances that dissociate to form hydroxide ions.

Define neutralization reaction.

A neutralization reaction is the reaction between hydronium and hydroxide ions to produce water.

What is a weak base?

A weak base is a substance that partially ionizes in solution.

Formula for molarity (concentration).

Molar concentration (M) = moles of solute / volume of solvent in liters (C=n/V).

Effect of temperature on gas solubility.

The solubility of a gas decreases with an increase in temperature.

What does a pH meter measure?

A pH meter measures the voltage produced by a solution containing hydronium ions and converts it into a pH reading.

What is the equilibrium condition for dissolving and crystallization?

A saturated solution is in equilibrium when the dissolving rate equals the crystallization rate.

What is the process of crystallization?

Crystallization is the formation of solid crystals from a solution as solute particles come together.