2.1.3 Amount Of Substance Flashcards
What is the symbol for amount of substance?
n
What is the unit used to measure amount of substance?
Mole
What does the Avogadro constant represent?
The number of atoms per mole of the carbon 12 isotope
How to calculate the mass of one mole of the element
Mass of one mole = relative atomic mass in grams
State Avogadro law
Under the same temperature and pressure one mole of any gas would occupy the same volume
How much volume does a gas occupy at room temperature and pressure?
24 dm³ or 24,000 cm³
Define molar gas volume
The volume per mole of gas molecules
Why do different gas particles occupy the same volume?
The gas particles are very spread out, hence individual differences has no effect
What is the ideal gas equation?
pV=nRT
One atmospheric pressure is equal to how many Pascal
1 atm = 101,325 Pa
0° C is equivalent to how many kelvin?
273K
What does concentration of a solution mean?
The amount of solute dissolved in one decimetre cubed of solvent
What is a standard solution?
A solution of known concentration
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
-the reactants may be impure
-side reactions could happen
-reactants or products may be left behind while transferring
-loss of products during separation and purification
What does atom economy tell us about?
The proportion of desired products compared with all the products formed in the reaction
How is atom economy calculated?
Atom economy = (molecular mass of desired products/ sum of molecular mass for total products) x100
Does 100% yield mean 100% economy?
No, even if all the reactants are converted into products, not all the products of the reaction will be the required products
Which type of reaction has 100% atom economy?
Addition reactions
