Chemistry (Moles : Case 3,4 & 5)

Case 3

Moles = Molar concentration (mol/dm3) x Volume (dm3)

Case 4

Mass (g) = mass concentration (g/dm3) x volume (dm3)

Case 5 (Avogadro’s Law)

All gases occupying the same volume under the same conditions of temperature and pressure, contain the same number of particles (6.022 × 10²³)

STP

Standard Temperature and Pressure - 0 deg Celsius or 273 K of 1 atm (101 kPa, 101,000 N/m²). Vm (Molar volume) is 22.4 dm³ or 22,400 cm³

RTP

Room Temperature and Pressure - 20 deg Celsius or 293 K of 1 atm. Vm is 24dm³ or 24,000cm³

Titration

This is a technique commonly used to determine the exact value of acid needed to neutralize a fixed volume of aqueous alkali.

Neutralization point

Point in an acid-alkali reaction where the reaction is complete and neither acid nor alkali is present.

Proton acceptor

Base

Involves performing a titration to determine the exact volume of one solution, usually an acid, required to neutralize a fixed volume of another solution.

Acid-base titration

Analyte

The solution of unknown concentration but known volume (amount).

Avogadro’s Law

States that equal volumes of gases, under the same conditions of temperature and pressure, contain the same number of molecules.

An auxiliary substance that helps in the detection of the completion of the titration process at the endpoint. Ex. Phenolphthalein

Indicator

Alkali

A soluble base

Neutralization

A reaction between a base and an acid.

Acid

Proton donor

Molar volume (22.4 L at STP, 24.0 L at RTP)

The volume of a gas that contains one mole of a substance.

Standard solution

A solution of known concentration