B5 how much? Quantitative analysis Flashcards
(59 cards)
One mole =
24g
How many atoms in one mole
6x10to the power if 23
How to calculate the number if moles
Mass in g / molar mass in g
/=divide
Mnemonics for molar mass and number of moles
Never -no. Of moles
Cut- concentration
Veins- volume
What does real active atomic mass equal
Molar mass
What does conservation of mass mean
Mass of reactants = mass of products
%compositon =
G of element / g of whole composition or element x100
What % of CuO is Cu?
64/80 x100 = 80%
What does empirical formula mean
The simplest ratio between the elements
C4 h10 into the empirical formula
C2 h5
How do I get from cm to dm
Cm divided by 1000 = dm
Dm x1000 =cm
Dilution:
Volume of water to add
(Start concentration /target concentration -1 )
X start volume
Concentration is measured in …
Mol/ dm3 cubed
What is salt
Sodium chloride NaCl
Why is salt good ?
Important for nervous system
Water balance
Blood pressure
Why is salt bad?
Too much and it gives you night blood pressure
Titrations and ph indicators
What is a single indicator
One with a single colour change
What is a mixed colour indicators
One with several colour changes to show the whole ph scale
Why are single indicators better
They have an end point. This is due to the fact they they only have one colour change
Concentration=
No of moles divided by volume
What does in excess mean
To have to much in reactions it is usually the acid
What does equilibrium mean
It shows that some reactions are reversible
The reactants =the products
Changing equilibrium the temperature
All reactions are exothermic in one direction
If you decrease the temp the equilibrium with move to compensate. It will more in the exothermic direction to make more heat
If you raise the temp the equilibrium will move to decrease it. It moves in the endothermic way
Changing equilibrium pressure
This involves gas
Increase it and the equilibrium tries to reduce it by moving toward the side with the fewer moles of gas and vice versa
