Amount of Substance

Question 1

What is the symbol for amount of substance

Answer 1

N

Question 2

What is the unit used to measure amount of substance

Answer 2

Mole

Question 3

What does the avogadros constant represent

Answer 3

The number of atoms per mole of the carbon 12 isotope

Question 4

How do you Calculate the mass of 1 mole of an element

Answer 4

mass of 1 mole= RAM in grams

Question 5

How do you calculate moles when mass and molar mass are given

Answer 5

Moles(Mol)= Mass(g) / Molar mass (g mol^-1)

Question 6

What is avogradros law

Answer 6

Under the same temp and pressure one mole of any gas would occupy the same volume

Question 7

How much volume does a gas occupy at room temp and pressure

Answer 7

24dm^3 or 24,000 cm^3

Question 8

Define molar gas volume

Answer 8

The volume per mile of gas molecules

Question 9

Why do different particles occupy the same volume

Answer 9

The gas particles are very spread out hence individual differences has no effect

Question 10

How do you calculate moles when gas volume is given?

Answer 10

Moles= volume (dm3) / 24
or
Moles= volume (cm3) / 24000

Question 11

What are the ideal way in which gases behave (5)

Answer 11

They are in continuous motion
No intermolecular forces are experinced
Exert pressure when they collide with each other or the container
No kinetic energy is lost in the collisions
When temperature increases the kinetic energy also increases

Question 12

What is the ideal gas equation

Answer 12

PV=NRT
Pascals x volume (m^3)= Number of moles x gas constant (8.314) x Temperature (kelvin)

Question 13

How much is 1 atmospheric pressure equal to in pascals

Answer 13

101325 pascals

Question 14

0 degrees celcius is equivalent to how many kelvins

Answer 14

273 kelvin

Question 15

What does concentration of a solution mean

Answer 15

It is the amount of solute dissolved in 1 dm^3 of solvent

Question 16

How do you calculate moles when conc and vol are given

Answer 16

moles = conc x vol

Question 17

What is a standard solution

Answer 17

A solution of known conc

Question 18

What does the term concentration mean

Answer 18

large amount of solute per dm^3

Question 19

What does the term dilute mean

Answer 19

small amount of solute per dm^3

Question 20

What is a species in a chemical reaction

Answer 20

any particle that takes part in the reaction

Question 21

What are the 4 common state symbols

Answer 21

Gas(g)
Liquid(l)
Solid(s)
Aqueous (aq)

Question 22

What does percentage yield mean

Answer 22

The efficient of which reactants are converted into products

Question 23

What are the reasons for not obtaining 100% percebtage yie;d

Answer 23

Reaction may be at equilibrium
The reactants may be impure
Side reactions could happen
Reactants or products may be left behind while transferring
Loss of products during separation and purifciation

Question 24

How is pervenatge yield calculated

Answer 24

Percentage yield=Actual amount of product/ theortical amount of product x100

Question 25

What does atom economy tell you

Answer 25

The proportion of desired products compared with all the products formed with the reaction

Question 26

How is atom economy calculated

Answer 26

Atom economy= Molecular mass of desired product/sum of the molecular masses of all products x 100

Question 27

How do you know when relative formula mass is used

Answer 27

Mr( relative formula mass) is used for ionic compounds becaus ethey dont exist as molecules

Question 28

Equation for number of moles

Answer 28

Number of moles=Mass/Mr

Question 29

Define solution

Answer 29

A solution consists of a solvent with a solute dissolved in it

Question 30

Formula for conc

Answer 30

Conc(moldm^3)=Number of moles/Volume(dm^3)

Question 31

How many decimetres are there in 1000cm^3

Answer 31

1dm^3

Question 32

Formula for number of moles in a solution

Answer 32

Conc(dm^3)x Vol(cm^3)/1000