quantitative chem Flashcards
What is the unit chemical quantities are often measured in?
Moles
What is the Avagadro constant? (described in words)
The number of atoms, molecules or ions in a mole of a given substance.
What is the numerical value of the Avagadro constant?
6.02X10 to the power of 23
How do you calculate the mass of a substance?
Relative formula mass x amount
How do you calculate the number of moles?
Mass divided by molar mass
What is meant by a ‘limiting reactant’?
The reactant in a chemical reaction that is completely used up as it limits the amount of products
What is the equation for concentration?
Mass (grams) divided by volume of solution
What is the equation triangle for moles and mass?
Mass(g)
—————
Moles x Mr
What is the equation triangle for concentrations of solutions?
Mass(g) or No. of moles
—————————————
Conc.(g/dm3) x volume(dm3)
How do you calculate volume of gas (dm3)?
No. of moles x 24
How do you convert from cm3 to dm3?
Divide by 1000
How many dm3 is 1 mole of gas that is under room temperature?
24dm3
What is the equation for percentage yield?
Amount of product produced(g)
———————————————. X100
Max amount of product possible(g)
What is the equation for atom economy?
Mr of desired product from the reaction
———————————————————. X100
Sum of the Mr of all the reactants
