Stoichiometry Involving Molar Concentration：涉及的摩尔浓度的化学计量比.ppt

Stoichiometry Involving Molar Concentration：涉及的摩尔浓度的化学计量比
What is Stoichiometry?
Stoichiometry is the relationships y
Convert given quantity to # of mol of quantity
If given quantity in L: use STP to convert
STP= 1 mol/ L
If given quantity in particles: Use Avogadro’s Number to convert
× 10^23
Step 2: Balance the Equation
2Al(s) + 2NaOH(aq) + 2H2O(l)  2NaAlO2(aq) + 3H2(g)
Step 3: Find mole of given quantity
Given quantity: Hydrogen gas at STP.
Moles of H2 = (1mol/) = mol H2
Step 4: Molar Ratio
Moles of given quantity: mol of H2
Moles of wanted quantity: ? Mol of NaOH
2Al(s) + 2NaOH(aq) + 2H2O(l) -> 2NaAlO2(aq) + 3H2(g)
2 : 3 ratio (mol of NaOH: mol of H2)
2:3 = 2/3
Mol(NaOH)= mol H2 (2 mol NaOH/3 mol H2)= mol NaOH
What volume of NaOH solution is required?
mol NaOH (step 4 answer)
sodium hydroxide (NaOH) solution (given)
Volume(v) = Mole(n)/ Concentration(c)
(Rearranged Molarity equation)
Volume of NaOH = ( mol) / () = NaOH
You Are Done!
Answer: of Sodium Hydroxide (NaOH) solution was required.
ALL IT TAKES IS THESE 5 SPECIAL STEPS!
Still having troubles remembering how to do these questions?
NO WORRIES!
We have a song to help you!
If I were a Mole Lyrics
*Tune: ‘If I were a Boy’ by Beyonce Knowles
If I were a mole even just for a day
I’d get up every morning just to
Do stoichiometry problems…

I love those questions
With molar concentration
Except I always had a
Secret to solving all these tricky ones.
If I were a mole
I could always understand
How you could solve this question
With five really ea-s-y steps
Remember tha-at
Molar Concentration
Is c equals n over v
It’s also called molarity
And you can use STP to solve
If I were a mole
The first big step is to
Write out a proper equation
With all the right element symbols
Step two is to-oo
Balance the equation both sides
‘cause all elements need to have
sam