Parts-per-million is a form of concentration that is confusing to some. It is often used for aqueous solutions at low concentrations because, as you state in your question, in dilute solutions the density of water has not been affected ie. is still 1.00 g/mL.
parts per million is defined as micrograms of solute per milliliter of solution. This doesn't inherently make sense since micrograms are on the millionths scale, but mL are on the thousandth scale, so it would seem to be millionth per thousandth--Not so! Since the 1.00 mL of water weighs 1.00 g, ug/mL converts, for dilute aqueous solutions, to ug/g, which now makes sense as parts per million. So, from the information given, the calculation is quite simple:
0.0036 g Cl * 10^6 ug/1 g = 3600 ug Cl
1.00 L * 1000 mL/1L = 1000 mL
Concentration of Cl- in solution in ppm:
3600 ug Cl- / 1000 mL = 3.6 ppm Cl-
Answer:
34.2 g
Explanation:
In the Hall-Heroult process, Al³⁺ (from Al₂O₃) is reduced to Al. The reduction half-reaction is:
Al³⁺ + 3 e⁻ ⇒ Al
We can establish the following relations:
- 1 A = 1 c/s
- 1 mole of e⁻ has a charge of 96468 c (Faraday's constant)
- 1 mol of Al is produced when 3 moles of e⁻ circulate
- The molar mass of Al is 26.98 g/mol.
Suppose a current of 6800 A is passed through a Hall-Heroult cell for 54.0 seconds. The mass of Al produced is:
![54.0s.\frac{6800c}{s} .\frac{1mole^{-} }{96468c} .\frac{1molAl}{3mole^{.} } .\frac{26.98gAl}{1molAl} =34.2gAl](https://tex.z-dn.net/?f=54.0s.%5Cfrac%7B6800c%7D%7Bs%7D%20.%5Cfrac%7B1mole%5E%7B-%7D%20%7D%7B96468c%7D%20.%5Cfrac%7B1molAl%7D%7B3mole%5E%7B.%7D%20%7D%20.%5Cfrac%7B26.98gAl%7D%7B1molAl%7D%20%3D34.2gAl)
There are 1.078 x 10²³ molecules
<h3>Further explanation</h3>
Given
4 dm³ = 4 L Nitrogen gas
Required
Number of molecules
Solution
Assumptions on STP (1 atm, 273 K), 1 mol gas = 22.4 L, so for 4 L :
mol = 4 : 22.4
mol = 0.179
1 mol = 6.02 x 10²³ particles(molecules, atoms)
For 0.179 :
= 0.179 x 6.02 x 10²³
= 1.078 x 10²³
16.00 grams of oxygen
since in one mole the mass would be the molecular mass, which is found on the periodic table
Answer:
second carbon atom from the end
end carbon atom
Explanation:
Carbohydrates are naturally occurring organic compounds containing carbon, hydrogen and oxygen. The general molecular formula of Carbohydrates is
.
Carbohydrates can be classified based on structures,
Carbohydrates with the structure of alkanals (-CHO) are known as aldose while those of the structure of alkanones (C=O) are known as ketose.
In stereochemistry , D series is a kind of configurational arrangement where the hydroxyl group attaches itself to the right hand side.
Thus; in naturally occurring D series of ketoses, the carbonyl group is found on carbon number <u>second carbon atom from the end </u>whereas in aldoses, the carbonyl group is found on carbon number <u> end carbon atom.</u>