Moles, Atoms And Trends

Question 1

How to calculate percentage composition of an element from a whole substance?

Answer 1

Divide the molar mass of the specific element by the molar mass of the whole substance and multiply by 100%

Question 2

How do you find the empirical formula?

Answer 2

Find moles of each element, divide all by smallest number of moles to find the ratio to create the formula

Question 3

How to find the amount of something in a set number of molecules/particles?

Answer 3

Use the formula:
Amount(mol) = particles / Avogadros

Question 4

How do you find an excess and/or limiting reagent?

Answer 4

Find moles of each element or substance then divide by Mol coefficient.
Smaller=limiting
Larger=excess

Question 5

How can you calculate the amount of a product through limiting and excess reagents?

Answer 5

Create a mol ratio with the limiting reagent the substance unknown, rearrange to find moles and then calculate for mass

Question 6

What is the formula for percentage yield?

Answer 6

% = experimental / theoretical ×100%

Question 7

What is Boyles Law?

Answer 7

P1V1 = P2V2

Question 8

What is Charles Law?

Answer 8

T1/V1 = T2/V2

Question 9

What is Gay-Lussacs Law?

Answer 9

P1/T1=P2/T2

Question 10

What is the combined gas law?

Answer 10

P1V1/T1 = P2V2/T2

Question 11

What is the formula for concentration?

Answer 11

[ ] = n/v

Question 12

Difference between a solute and solvent

Answer 12

Solute:
Less abundant, being dissolved, s, g or l
Solvent:
More abundant, does the dissolving, usually liquid

Question 13

Mass spectrometer

Answer 13

Used to measure mass to charge ratio. Consists of ionization, acceleration, deflection and detection

Question 14

What are the 2 exceptions to the filling order?

Answer 14

Cr, add 4s to last 3d box
Cu, add 4s as spin down in last 3d box

Question 15

What is an electron arrangement?

Answer 15

Just the total e from each level.