Question

Explain how to make 200 mL of 2 M sodiun hydroxide (NaOH)

Answer 1

Do you that C = n/V?

Answer 2

i need to know how to do it

Answer 3

But do you know that equation?

Answer 4

(Its important in solving this problem)

Answer 5

ok i understand that a mole is 6.02x10^23 of anything

Answer 6

...
Concentration ( mol / L) = n ( number of moles) / Volume ( L)

You know both the concentration, and volume of the solution you want to make
2M is the equivalent to 2 mols per L
And the volume you have is in mL, so you have to change it to L

Using C = n/v, you can find the number of moles, and since you have the compound, you can find its' molar mass

Knowing the fact that mass of a compound is the number of moles times molar mass.
You can find the amount of sodium hydroxide (NaOH) needed to create the solution

Answer 7

so i can use the equation C=n/v

Answer 8

Yeah.. but you have to converl mL to L

Answer 9

And rearrange for n, moles..

Answer 10

ok give me one and ill try to do do beacuse im still not unstanding

Answer 11

one what

Answer 12

example like a gave before

Answer 13

V = 200mL or 0.2L (divide by 100)
C = 2M = 2mol/L
C = n/V
=> n = CV, then n = (2mol/L)(0.2L), Litres cancel and you have mol
=> n = 0.4 mols,
molar mass of NaOH = 22.99 g/mol + 16.00 g/mol + 1.01 g/mol
To find out much mass you have to dissolve into 200mL of water to make a 2 mol/L solution of NaOH, you multiply 40g/mol * 0.4 mol to get 16 g

Answer 14

how u get 0.2

Answer 15

V = 200mL or 0.2L (divide by 1000)

Answer 16

y u use 100

Answer 17

type

Answer 18

typo

Answer 19

1000 mL = 1 L...

Answer 20

so i divide it by 1000

Answer 21

Yes.. 200mL / 1000 gives you a number in L

Answer 22

im sorry is there is there a way i can email u and u can explain it like that because there is no way i can get the full undwrstanding if im trying focus on this and thaat

Answer 23

Id really prefer if we'd do it here

Answer 24

im tryinh yo understand

Answer 25

The thing is you want to make a solution that has a concetration of 0.2 moles per litre.
You want do dissolve a certain mass of NaOH into 200mL of water to make that..

Answer 26

ok i understand that

Answer 27

next

Answer 28

In order to find the mass of NaOH you want to dissolve, you have to find the number of moles you need.

Using C = n/V, since you have the both the concentration and volume of the solution you want to make, you can find the number of moles that need to be dissolved

Answer 29

ok give me a example like make up one

Answer 30

Molecular weight of NaOH=40 g.
Molarity = No of moles/litre
If you want to preperae 2M,200 ml
2*40*0.2= 16 g
Take 16g NaOH and dissolve in water in a standard flask upto 200ml.

Answer 31

how iw u get 0.2

Answer 32

200 ml=0.2 litre