posted by Dylan on .
I'm not sure how to do a couple of problems on my chemistry worksheet. Can you please help me?
You dissolve 0.00902 g of naOH in enough water to make 1000 mL. What is the Ph of this soultion.
What is the molarity, pH, and pOH of 5.00 of naOH in 750.0 mL of soultion. I know how to do the pH and the pOH usaully but how do I do it with the g?
You take 2 mL of 18.0 M H2SO4 and add it to 998 mL of wate4r. What is the pH and pOH?
Can you please show me how to do these... I'm lost. Thanks
convert the grams to moles.
Molarity=mass/molmass / volumesolution
= .00902/40*1 = you do it.
Now the dissociation equation:
NaOH>>Na+ + OH-
completely dissociated, so the moles of NaOH become the concentration of Na+, and OH-
pOH= -log(molarity above)
same thing on the sulfuric acid, except the molarity determination.
moles of H2SO4=.002*18=.036
or another way:
you are diluting it 1000/2=500 times, or new molarity= 18/500=.036M