2.1.3 Amount of Substance Flashcards
What is the symbol for amount of substance?
n
What is the unit used to measure amount of substance?
Mole
What does the Avogadro constant represent?
The number of atoms per mole of the carbon-12 isotope
How do you calculate the mass of 1 mole of an element?
Mass of 1 mole = relative atomic mass in grams
How to calculate moles when mass and molar mass are given?
Moles (mol) = mass (g) / molar mass (g mol*-1)
State avogadro’s law
Under the same temperature and pressure, one mole of any gas would occupy the same volume
How much volume does a gas occupy, at room temperature and pressure?
24 dm3 or 24000 cm3
Define molar gas volume
The volume per mole of gas molecules
Why do different gas particles occupy the same volume?
The gas particles are very spread out, hence individual differences has no effect
How do calculate moles when gas volume is given?
Moles (mol) = volume (dm3) / 24
Or
Moles (moles) = volume (cm3) /24000
What are the ideal ways in which gas behaves? (5)
•They are in continous motion
•No intermolecular forces experienced
•Exert pressure when they collide with each other or container
•No kinetic energy is lost in the collisions
•When temperature increases , kinetic energy of gases also increase
Write down the ideal gas equation (in words and symbols, including units)
pV = nRT
Pressure (Pa) x volume (m3) = number of moles (mol) x gas constant (8.314 J mol-1) x temp (K)
1 atmospheric pressure is equal to how many pascals?
1 atm = 101325 Pa
0 degrees celsius is equal to how many kelvin?
273 K
What does concentration of a solution mean?
It is the amount of solute dissolved on 1 dm*3 of solvent