Answer: -
The concentration is 0.91 mol/ L
Explanation: -
The osmotic pressure = 23 atm
Absolute temperature = 309 K
Universal gas constant = 0.08206 L atm mol⁻¹ K⁻¹
We know the formula
Osmotic pressure = molar concentration x universal gas constant x absolute temperature
Plugging in the values
23 atm = molar concentration x 0.08206 L atm mol⁻¹ K⁻¹ x 309 K
Molar concentration =
mol/ L
= 0.91 mol / L
Answer:
6%
Explanation:
Hello, for this case, we assume that the volume of the solution is 1L, thus, the mass is given by using the density as follows:

Now, the mass of the ethanol:

Finally, the by mass percent is:
%
%m=6%
Best regards.
Answer:
Sulfur: -1
Carbon: 0
Nitrogen: 0
Explanation:
The thiocyanate ion SCN- can have only two resonance structures, which are:
S - C ≡ N <--------> S = C = N
In the first structure, we have one single bond and one triple bond, in this case, the negative charge is located in the sulfur. This is because Sulfur have 6 electrons and those electrons are present in the atom, (see picture below), and counting the electron that is sharing with the Carbon, the total electrons that sulfur has is 7 (It has one more than usual). Carbon and nitrogen are already stable with 0 of formal charge, because carbon can only have 4 electrons which 1 is sharing with sulfur and the other 3 with the nitrogen, and nitrogen have 5 electrons, three sharing with carbon and the other two kept it for itself.
In the second structure, the negative charge of the sulfur is transfered to the nitrogen, meaning that it has 6 electrons the nitrogen (formal charge -1) and carbon and sulfur with 4 and 6 electrons respectively.
Between these two structures, the most stable is the first one basically because Sulfur is a better nucleophile than the Nitrogen, and can form stronger hydrogen bond in acid, giving more stable structure.
Well the answer to number 1 is definitely B
number 2 is B
number 3 is D
Number 4 is C
Hope this helps:)
Moles of Zn: 26 / 65 = 0.4
Moles of S: 12.8 / 32 = 0.4
Molar ratio of Zn : S = 1 : 1
Empircal formula: ZnS
The answer is C