Amount of Substance (Ch2)

Question 1

State Avogadro’s constant

Answer 1

6.022 x 10^23

Question 2

Define Avogadro’s constant

Answer 2

The number of moles in 12g of Carbon-12

Question 3

Define a mole

Answer 3

The amount of substance that contains 6.022 x 10^23 particles

Question 4

State the equation for moles, Mr and mass

Answer 4

mass = moles x Mr

Question 5

State the equation for volume, concentration and moles

Answer 5

moles = volume x concentration (mol/dm3)

Question 6

State the equation for volume, mass and concentration

Answer 6

mass = volume x concentration (g/dm3)

Question 7

State the ideal gas equation

Answer 7

PV=nRT

Question 8

State the value of R in the ideal gas equation

Answer 8

8.31

Question 9

State the units for the ideal gas equation

Answer 9

P (Pa)
V (m^3)
n 
R (J/KelvinMole)
T (K)

Question 10

What three steps would you use in a long empirical formula question?

Answer 10

• Find the masses of each element
• Find the moles of atoms of each element
• Find the simplest ratio

Question 11

Define empirical formula

Answer 11

• The formula which gives the number of atoms in a molecule in their simplest ratio

Question 12

Define molecular formula

Answer 12

• The formula which gives exactly how many atoms in a single molecule of the substance

Question 13

Give the formula for atom economy

Answer 13

atom economy = mass of desired product / mass of total product

Question 14

Give the formula for percentage yield

Answer 14

% yield = number of moles yield of a specified product / theoretical maximum yield of product