pH calculation (1 Viewer)

[untouchablecuz]

Calculate the pH of a solution of 0.75 g barium hydroxide dissolved in 2.0 L
water.

I think I got the answer, I just need reassurance

 

[katie tully]

well moles would be easy to work out from 0.75 g of barium hydroxide/mw

but

u tell us what you got first....

 

[katie tully]

we can even work out da molaritiez!

 

[katie tully]

>=}

no .. it doesn't mater ... im just saying we can

 

[katie tully]

nm, stalling, procrastinating ... all of those other words that describe the art of evading assignments

u?

 

[katie tully]

tee hee

when the AU dollar was 90 us cents or whatever, i got 2 text books incl. postage thru amazon for less than the cost of one text with postage thru the coop

:wave:

 

[untouchablecuz]

i got pH = 11.34

not 100% if it's correct cause there's a step i'm not sure of (but it fits with the substance, basic)

and btw, thanks for the help guys LOL

edit: i'm pretty sure i got it wrong

 

[lolokay]

molar mass of Ba(OH)₂ = 137.3 + 2(16.00 + 1.008)
= 171.3g

so there are 0.75/171.3 = 4.38 * 10^-3 moles of Ba(OH)₂ in the 2.0L
So [OH^-] = 2*(4.38 * 10^-3)/2.0 as there are 2 OH^- for each Ba(OH)₂
[OH^-] = 4.38 * 10^-3

using [OH^-][H⁺] = 10^-14 for water
[H⁺] = 10^-14/ [OH^-]
= 2.28 * 10^-12

pH = -log[H⁺]
= 11.64