Answer:
Standardisation is used to determine the concentration of a volumetric solution in order to achieve accurate and reliable titration results
Answer:
D H2PO4– + HPO42–
Explanation:
The acid dissociation constant for 
are 
respectively.
The reason while option D is the best answer is that, the value of pKa for both
lies on either side of the desired pH of the buffer. This implies that one is slightly over and the other is slightly under.
Using Henderson-Hasselbach equation:
Answer:
Molecules
Explanation:
If you had more than one atom chemically bonded together, then regardless of the types of atoms that are bonded, you're going to have a molecule regardless.
I feel like all of them are true
Answer:
The correct answer is 0.047 mol/L
Explanation:
The atmospheric air is a mixture of gases. We can assume an ideal behavior of the gas and use the ideal gas equation:
PV= nRT
where P is the pressure, V is the volume, n is the number of moles, R is a constant (0.082 L.atm/K.mol) and T is the temperature in K.
We have to first convert the pressure from Torr to atm:
760 Torr= 1 atm
⇒ 718 Torr x 1 atm/760 Torr = 0.945 atm
Then, we convert the temperature from ºC to K:
0ºC = 273 K
⇒ -29ºC+273= 244 K
Finally, we introduce the data in the equation and calculate de densitiy, which is the moles per liters of gas (n/V):
PV = nRT
n/V= P/RT
n/V = (0.945 atm)/(0.082 L.atm/K.mol x 244 K) = 0.047 mol/L
