Amount Of Substance Flashcards
What is the symbol for amount of substance
N
What is the unit used to measure amount of substance
Moles
Wha does avagadros constant represent
The number of atoms per mole of carbon-12
How to calculate the mass of 1 mole of the element
Mass of one mole = relative atomic mass in grams
How to calculate moles when mass and molar mass are given
Moles= mass / molar mass
State avagadros law
Under the same temperature and pressure, one mole of any gas would occupy the same volume
Define molar gas volume
The volume per mole of gas molecules
Why does different gas particles occupy the same volume
The gas particles are very spread out, hence individual differences has no effect
How much volume does a gas occupy at room temp and pressure
24 dm3 or 24000cm3
How to calculate moles when gas volume is given
Moles = volume/ 24
What are the ideal ways gasses behave
-they are in continuous motion
-no intermolecular forces experienced
-no kinetic energy is lost in collisions
Exert pressure when they collide with each other or container
-when temperature increases kinetic energy of gasses also increase
Write down the ideal gas equation
pV= nRT
Pressure x volume = number of moles x gas constant x temperature
1 atmospheric pressure is equal to how many pascal
1 atm = 101325 Pa
0 degrees C is equal to how many kelvin
273K
How do you calculate moles when concentration and volume are given
Moles = concentration x volume
What is a standard solutions
A solution of known concentration
What does the terms concentrated ad dilute mean
Concentrated- large amount of solute per dm3 of solvent
Dilute- small amount of solute per dm3 of solvent
What is a species in a chemical reaction
Any particle that takes part in a reaction
What are the 4 common state symbols
- s
-l
-g
Aq
What does percentage yield mean
The efficiency of which reactants are converted into products
What are the reasons for not obtaining 100% yield
-reaction may be at equilibrium
- side reactions
-impure reactants
-loss of product
-reactants or product may be left behind while transferring
How is percentage yield calculated
Percentage yield = actual/ theoretical x 100
What does atom economy tell us about
The proportion of desired products compared with all the products formed in a reaction
How is atom economy calculated
Atom economy= molecular mass / sum of all molecular masses x 100
Does 100% yield mean 100% atom economy
No, even if all the reactants are converted into products not all products of the reaction will be the required products
Which type of reaction has 100% atom economy
Addition reactions
