CHAPTER 3: AMOUNT OF SUBSTANCES

Question 1

What is the equation for percentage mass?

Answer 1

(Ar x number of atoms in element) / Mr of the compound

x 100

Question 2

What is the equation that links moles, mass and Mr?

Answer 2

moles = mass / Mr

Question 3

What is the equation that links volume, moles and 24?

Answer 3

volume of gas = moles x 24dm or 24000cm

Question 4

What is the equation that links moles, concentration and volume?

Answer 4

moles = concentration x volume

Question 5

What is the equation that links concentration, moles of solute and volume of solute?

Answer 5

concentration = moles of solute / volume of solute

Question 6

What is the equation for atom economy?

Answer 6

atom economy = (relative formula mass of desired products / relative formula mass of all reactants) x 100

Question 7

What is the equation for percentage yield?

Answer 7

percentage yield = (mass of an actual product / theoretical mass of product) x 100

Question 8

What is Avagrado’s constant?

Answer 8

6.02 x 10*23. This is the number of particles in each mole of carbon-12

Question 9

How do you convert gram/dm3 to mol/dm3

Answer 9

divide Mr

Question 10

How do you convert mol/dm3 to gram/dm3

Answer 10

x Mr

Question 11

What is amount of substance?

Answer 11

The number of particles in a substance

Question 12

What is molecular formula?

Answer 12

The number of atoms in each element of a molecule

Question 13

What is empirical formula?

Answer 13

The simplest whole number ratio of atoms of each element in a compound