C3: Quantitative Chemistry (triple)

Question 1

What is relative formula mass?

Answer 1

The relative atomic masses of all the atoms in the molecular formula added together.

Question 2

What is a mole?

Answer 2

The amount of a element or compound that has the same mass (g) as the relative atomic mass value of an individual atom or molecule.

Question 3

Number of moles=

Answer 3

Mass in grams / relative atomic mass

concentration * volume

Question 4

Concentration=

Answer 4

Mass of solute / volume of solvent

number of moles of solute / volume of solvent

Question 5

atom economy=

Answer 5

(relative formula mass of desired product / relative formula mass of all reactants) * 100

Question 6

Percentage yield=

Answer 6

(mass of produce actually made / maximum theoretical mass of product) * 100

Question 7

What 3 reasons mean that yield are always less than 100%?

Answer 7

1. not all reactants react to make products
2. there may be side reactions
3. you lose some product when you separate it form the reaction mixture