Question

Teaching! How to manipulate formulas? How to make something as subject? :)

Answer 1

@CaseyCarns alright lets start :)

Answer 2

tell me all formulas that you learnt and know about in chemistry

Answer 3

So molarity is M = moles solute/liters solution

Answer 4

tell me all the formulas

Answer 5

C1V1= C2V2

Answer 6

C1m1= C2m2

Answer 7

mole = conc*dm3

Answer 8

mass = mole*Mr

Answer 9

no no
look

Answer 10

most common formulas are
\[concentration = \frac{ mole }{ volume }\]
\[mole = \frac{ mass }{Molecular mass }\]
\[C1V1= C2V2\]
\[C1m1= C2m2\]
\[\frac{ P1V1 }{ T1 } = \frac{ P2V2 }{ T2 }\]
\[PV=nRT\]

alright lets have fun with these formulas :)

Answer 11

okay lets start with first one
i'll write concentration as C and volume as V ok?

Answer 12

Okay

Answer 13

so
\[C = \frac{ mole }{ V }\]

Answer 14

now i want to make V as subject

Answer 15

That's when we find V?

Answer 16

no not yet

Answer 17

okay so look
actually the formula looks like this
\[\frac{ C }{ 1 } =\frac{ mole }{ V }\]

Answer 18

Okay

Answer 19

we don't usually write 1 that's why the formula you know simply looks like this
C=mole/V

Answer 20

are you familiar with cross multiplication from math?

Answer 21

Yes

Answer 22

ok then do it here

Answer 23

But theres no numbers?

Answer 24

yeah you are given basically letters
do it with them

Answer 25

So C*V and 1*mole

Answer 26

C*V= mole*1

Answer 27

right
now do u see what you just made as subject?

Answer 28

mole?

Answer 29

bingo!

Answer 30

now look
\[ \frac{ CV }{ 1 } = \frac{ mole }{ 1 }\]

Answer 31

its same formula you did but now i just made it as fraction

Answer 32

do u get it?

Answer 33

Yes I do

Answer 34

alright again now you want to make V as subject so

Answer 35

to make V as subject you do cross multiplication again BUT you leave V there to stay and become subject

Answer 36

Okay so when you multiply you just use C?

Answer 37

yes because you want V to be your subject

Answer 38

Okay!

Answer 39

so now you made V as subject
what formula u r getting?

Answer 40

what is this? @sweetburger

Answer 41

oh i know this

Answer 42

i meant what is that for?
she doesn't know all this

Answer 43

im teaching her how to manipulate formulas