Posted by candy on Tuesday, October 12, 2010 at 5:04pm.
1) How do I prepare 2M nitric acid from 65% concentrated nitric acid?
2) How do I prepare 17% ammonia from 25% concentrated ammonia?
Please show calculation steps. Thanks.
Chemistry -pls help urgent - DrBob222, Tuesday, October 12, 2010 at 5:33pm
Is that 65% and 17% w/w or w/v?
Do you have a density listed.
Chemistry -pls help urgent - candy, Tuesday, October 12, 2010 at 5:51pm
Assuming it is w/w as is the case for most acids and conc ammonia, can you show me the steps using 69% HNO3 and 28% ammonia?
I have density of 69% HNO3 as 1.42g/ml & 28% ammonia as 0.88g/ml.
this 17% ammonia is to dissolve my chloride ppt
see your original post.
Hi, if I want to prepare a w/v solution, how do I prepare it? Thanks a lot.
If it's the same 69% w/w with a density of 1.42, then we know it is 69g HNO3/100 g soln. 100 g soln has a volume of 70.4 mL so the solution is 69 g x 100/70.4 = 97.98 g/100 mL which I will round to 98 g/100 mL.
We want, say, 10% w/v.
10% w/v means 10 g HNO3/100 mL solution.
We have 98 g/100 mL so we want to take
100 mL x 10/98 = 10.2 mL of the concd solution and make to 100 mL final volume. Check my thinking.
To prepare a 2M nitric acid solution from 65% concentrated nitric acid, you need to know the density of the concentrated nitric acid. Unfortunately, you have mentioned the density of the 69% HNO3 solution, but not the 65% HNO3 solution. The density is needed to convert between weight percent and weight/volume percent.
Assuming the density of the 65% HNO3 solution is similar to that of the 69% solution, which is around 1.42 g/ml, we can proceed with the calculation. Here are the steps:
1. Determine the amount of concentrated nitric acid (65% HNO3) needed to make 2 moles of nitric acid.
The molar mass of HNO3 is:
H = 1 g/mol
N = 14 g/mol
O = 16 g/mol (x3)
Total = 1 + 14 + (16 x 3) = 63 g/mol
To prepare a 2M solution, we need 2 moles of HNO3. Therefore, the mass of HNO3 needed is:
Mass = 2 moles x 63 g/mol = 126 g
2. Convert the mass of concentrated nitric acid to volume using its density.
Volume (ml) = Mass (g) / Density (g/ml)
Volume = 126 g / 1.42 g/ml ≈ 88.7 ml
So, you need to measure approximately 88.7 ml of the 65% concentrated nitric acid and then dilute it with water to a final volume of 1000 ml to prepare a 2M nitric acid solution.
For the second question about preparing a 17% ammonia solution from 25% concentrated ammonia, we need the density of the 25% ammonia solution. Unfortunately, you have provided the density of the 28% ammonia solution. Without the proper density, it is not possible to perform the calculations.
Please provide the correct density of the 25% ammonia solution so that I can assist you further.