# Chemistry

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How many grams of nitric acid (HNO3) must be dissolved in 740 mL of water to make a solution with a pOH = 8.3?

• Chemistry - ,

The system N2O4 <--->2NO2 maintained in a closed vessel at 60º C & a pressure of 5 atm has an average (i.e. observed) molecular weight of 69, calculate Kp.
At what pressure at the same temperature would the observed molecular weight be (230/3)

• Chemistry - ,

The system N2O4 <--->2NO2 maintained in a closed vessel at 60º C & a pressure of 5 atm has an average (i.e. observed) molecular weight of 69, calculate Kp.
At what pressure at the same temperature would the observed molecular weight be (230/3)

• Chemistry - ,

just change the value
i found it on y!A

find the [H+} in pH of 4.5 ,
10^-4.5 =
[H+] = 3.16 e-5 molar

find the moles acid in 350 ml
0.350 litres @ 3.16 e-5 mol/litre =
1.11 e-5 moles of HNO3

find the grams using molar mass:
1.11 e-5 moles of HNO3 @ 63 g/mol =
0.00070 grams of HNO3
======================================…

@ pH of 2.9, find the H+:
10^-2.9 =
0.00126 molar H+

use the dilution formula:
C1V1 = C2V2
(4.2M) V1 = (0.00125M) (500ml)
V1 = 0.15 ml of 4.2 Molar is required

• Chemistry - ,

see same question
how many grams nitric acid HNO3 must be dissolved in 350 ml water to make a solution with pH of 4.5"?

or "how many ml of a 4.2M nitric acid solution are required to make 500 ml of solution with pH of 2.9