Chapter 2 Flashcards
(17 cards)
Define the mole.
The amount of substance containing as many particles as there are atoms in exactly 12 g of carbon-12.
What is Avogadro’s constant?
6.022 × 10²³ mol⁻¹, the number of particles in one mole of substance.
What is the equation linking moles, mass, and molar mass?
Moles = mass (g) ÷ molar mass (g/mol).
How do you calculate moles from concentration and volume?
Moles = concentration (mol/dm³) × volume (dm³).
Define relative molecular mass (Mr).
The sum of the relative atomic masses of all atoms in a molecule or formula unit.
How do you find empirical formula from experimental data?
Divide the masses or moles of elements by their smallest mole value to find the simplest whole number ratio.
What is the difference between molecular and empirical formula?
Molecular formula shows actual number of atoms, empirical shows simplest ratio.
Calculate number of particles in 2 moles of CO₂.
2 × 6.022 × 10²³ = 1.2044 × 10²⁴ particles.
What volume does one mole of any gas occupy at RTP?
24.0 dm³.
What is the ideal gas equation?
PV = nRT.
State the units used in the ideal gas equation for pressure, volume, and temperature.
Pressure in Pa, volume in m³, temperature in K.
Convert 25°C to Kelvin.
298 K.
What is the percentage yield formula?
(actual yield ÷ theoretical yield) × 100.
Define atom economy.
(mass of desired products ÷ total mass of products) × 100.
What is the significance of high atom economy?
It shows a more efficient reaction producing less waste.
Explain why percentage yield is rarely 100%.
Side reactions, incomplete reactions, loss during product recovery.
What is the relationship between moles and volume of gas at RTP?
Volume (dm³) = moles × 24.0.
