2.1.3 - Amount of Substance Flashcards
What is a mole?
The mole is the amount of substance in grams that has the same number of particles as there are atoms in 12 grams of carbon-12.
What is relative atomic mass?
Relative atomic mass is the average mass of one atom compared to one twelfth of the mass of one atom of carbon-12
What is molar mass?
Molar Mass is the mass in grams of 1 mole of a substance and is given the unit of g mol-1
How can the molar mass of a compound be calculated?
Molar Mass for a compound can be calculated by adding up the mass numbers(from the periodic table) of each element in the compound
What is molar gas volume?
Molar gas volume (gas volume per mole, units dm3 mol–1 ) . This is the volume of 1 mole of a gas at a given temperature and pressure. All gases have this same volume. At room pressure (1atm) and room temperature 25oC the molar gas volume is 24 dm3 mol–1.
What is avagadros constant?
There are 6.02 x 1023 atoms in 12 grams of carbon-12. Therefore explained in simpler terms ‘One mole of any specified entity contains 6.02 x 1023 of that entity’.
What is the formula to work out an amount, in moles?
Amount (in moles) = mass / mr
Convert 1000mg in grams.
1000mg = 1g
Convert 1000g into kilograms.
1000g = 1kg
What is the empirical formula?
An empirical formula is the simplest ratio of atoms of each element in the compound.
Convert 1000kg into tonnes.
1000kg = 1 tonne
What is a molecular formula?
A molecular formula is the actual number of atoms of each element in the compound.
What is the general method for calculating the empirical formula?
- Step 1 : Divide each mass (or % mass) by the atomic mass of the element.
- Step 2 : For each of the answers from step 1 divide by the smallest one of those numbers.
- Step 3: sometimes the numbers calculated in step 2 will need to be multiplied up to give whole numbers.
- These whole numbers will be the empirical formula.
What is the formula to calculate mass concentration?
Mass concentration = Mass / Volume
What is a solution?
A solution is a mixture formed when a solute dissolves in a solvent. In chemistry we most commonly use water as the solvent to form aqueous solutions. The solute can be a solid, liquid or a gas.
How do you convert Celsius into kelvin?
Celsius + 273 = K
What is mass concentration?
The concentration of a solution can also be measured in terms of mass of solute per volume of solution.
How is molar concentration calculated?
Molar concentration can be measured for solutions. This is calculated by dividing the amount in moles of the solute by the volume of the solution. The volume is measure is dm3 . The unit of molar concentration is mol dm-3 ; it can also be called molar using symbol M.
* Concentration = amount in moles / volume
What is the ideal gas equation?
PV = nRT
What does each letter of the ideal gas equation stand for?
P = unit of pressure = Pa
V = Unit of volume = m3
N = number of moles
R = gas constant = 8.31
T = unit of temperature = K
How do you calculate the number of particles in a compound?
Number of particles = amount of substance (in moles) x Avogadro’s constant.
What is the formula for calculating density?
Density = Mass / Volume
What is the formula for percentage yield?
Percentage yield = (actual yield / theoretical yield) x 100
What is the formula for percentage atom economy?
Percentage atom economy = (mass of useful products / mass of all reactants) x 100
