MODULE 2: Amount of Substance

Question 1

What is a mole?

Answer 1

A unit of measurement that measures the number of particles in a substance

Question 2

What is the Avogadro’s constant?

Answer 2

That one mole has 6.02 x 10^23 particles

Question 3

What is the equation for moles?

Answer 3

moles = mass/mr

Question 4

What is molecular formula?

Answer 4

The number of atoms of each elements in a molecule

Question 5

What is empirical formula?

Answer 5

Simplest whole number ratio of atoms of each element in a compound

Question 6

What is a hydrated salt?

Answer 6

Salts with water molecules as a part of the crystalline structure

Question 7

What is an anhydrous salt?

Answer 7

Salts without water molecules as a part of the crystalline structure

Question 8

What is the equation for moles in gases?

Answer 8

moles = volume(dm3)/24

Question 9

What is the ideal gas equation?

Answer 9

PV = nRT

Question 10

For the ideal gas equation, what does P stand for?

Answer 10

Pressure, Pa

Question 11

For the ideal gas equation, what does V stand for?

Answer 11

Volume, m3

Question 12

For the ideal gas equation, what does n stand for?

Answer 12

Moles, mol

Question 13

For the ideal gas equation, what does R stand for?

Answer 13

Ideal gas constant, 8.31 Jmol -1 K -1

Question 14

For the ideal gas equation, what does T stand for?

Answer 14

Temperature, Kelvin

Question 15

How do you convert cm3 to m3?

Answer 15

x 10 ^-6

Question 16

How do you convert dm3 to m3?

Answer 16

x 10 ^-3

Question 17

How do you convert oC to K?

Answer 17

+ 273

Question 18

How do you convert kPa to Pa?

Answer 18

x 10 ^3

Question 19

What is stiochiometry?

Answer 19

Balancing numbers to give the amount of moles

Question 20

What is the equation for percentage yield?

Answer 20

Percentage yield = actual yield / theoretical yield x 100

Question 21

What are some of the reasons percentage yield may be less than 100%?

Answer 21

The reaction may not have gone to completion, other reactions may have taken place along side the main reaction, purifying the product

Question 22

What is atom economy?

Answer 22

Atom economy is the efficiency of a chemical process in terms of all atoms involved and the desired products

Question 23

What is the equation for atom economy?

Answer 23

Atom Economy = molar mass(es) of desired product(s) / molar mass(es) of all product(s) x 100

Question 24

What aspects, other than a high atom economy, makes a reaction sustainable?

Answer 24

Using readily available/environmentally safe reactants, high percentage yield