Moles

Question 1

What is the relative formula mass (Mr) ?

Answer 1

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

Question 2

How do you calculate the percentage mass of an element in a compound?

Answer 2

percentage mass of an element in a compound = ((Ar * number of atoms of that element) / Mr of the compound) * 100

Question 3

What is Ar?

Answer 3

Relative atomic mass

Question 4

What is Avogadro’s constant?

Answer 4

602000000000000000000000 or 6.02 x 10^23

Question 5

What is a mole of substance?

Answer 5

The amount of a substance that contains an equal number of particles to Avogadro’s constant.

Question 6

How do moles relate to mass

Answer 6

1 mole of atoms or molecules of an substance will have a mass in grams equal to the Relative Formula mass (Ar or Mr)

Question 7

What is the formula to find the amount of moles in a given mass?

Answer 7

No. of moles = mass in g (Of an element or compound) / Mr (Of the element or compound)

Question 8

What is the percentage yield?

Answer 8

The amount of product that you receive from a reaction over the beginning amount

Question 9

Give the equation for percentage yield

Answer 9

percentage yield = mass of product actually made (grams) / maximum theoretical mass of product (grams)