Amount of a Substance

Question 1

What is a Mole?

Answer 1

A Mole is the Amount of a Substance that contains the Same Number of Particles as there are in 12g of Carbon-12

Question 2

What is the Symbol for Avogadro’s Constant?

Answer 2

Avogadro’s Constant (N_A)

Question 3

Define Avogadro’s Constant

Answer 3

Avogadro’s Constant is the Number of Particles in One Mole of a Substance

Question 4

What is the Value for N_A?

Answer 4

Avogadro’s Constant (N_A) = 6.02x10²³

Question 5

Define Molar Mass

Answer 5

Molar Mass (M_r) is the Mass of One Mole of a Substance

Question 6

Define Molar Gas Volume

Answer 6

Molar Gas Volume is the Number of Moles of a Gas in 1dm³ at a given Temperature & Pressure

Question 7

What does the Symbol M mean?

Answer 7

M is the Shorthand for Concentration (mol dm^-3)

Question 8

Give Both Formulas used to work out Mass

Answer 8

• Mass = Molar Mass x Number of Moles (Mr. Mole)
• Mass = Volume x Mass Concentration (g dm^-3)

Question 9

Give the Formula used to work out the number of Moles

Answer 9

Moles= Concentration x Volume

Question 10

How many cm are in a dm?

Answer 10

10cm make a dm

Question 11

How many cm³ are in a dm³?

Answer 11

1000cm³ are in a dm³

Question 12

How much space does One Mole of gas occupy at RTP?

Answer 12

One Mole of Gas occupies 24dm³ at Room Temperature & Pressure (RTP)

Question 13

Define Empirical Formula

Answer 13

Empirical Formula is the Simplest Ratio of the number of Atoms of each Element present in a Molecule

Question 14

Define Molecular Formula

Answer 14

Molecular Formula is the Actual number of Moles/Atoms of each Element present in a Molecule

Question 15

What is the Equation Linking:

• Pressure
• Number of Moles
• Volume
• Temperature
• Gas Constant

Answer 15

PV=nRT

Question 16

What is the Gas Constant?

Answer 16

The Gas Constant is 8.31 Jmol^-1K^-1

Question 17

In PV=nRT, What is Temperature Measured in?

Answer 17

Temperature is measured in Kelvin (K)

Question 18

How many Kelvin are in 0°C?

Answer 18

273K are in 0°C

Question 19

In the Equation PV=nRT, What is Volume measured in?

Answer 19

For PV=nRT, Volume is Measured in m³(1m³=1000dm³)

Question 20

In the Equation PV=nRT, Pressure is measured in…?

Answer 20

In The Equation PV=nRT, Pressure is measured in Pascals (Pa)

Question 21

Why might you get less than 100% Yield? (3 Reasons)

Answer 21

You may get less than 100% Yield because:

• The Reaction is Incomplete
• Other Reactions Occur
• Product is Lost

Question 22

What is the Formula for % Atom Economy?

Answer 22

% Atom Economy= (Desired Product Mass ÷ Total Mass) x100

Question 23

What is the % Atom Economy of a reaction with only 1 Product?

Answer 23

The % Atom Economy of a Reaction with One Product is 100%

Question 24

Would an Efficient Reaction have a High or Low Atom Economy?

Answer 24

An Efficient Reaction would have a High % Atom Economy

Question 25

Why are Reactions with High Atom Economys better for the Environment?

Answer 25

Less Natural Resources are Wasted when a Reaction has a High % Atom Economy