The new volume of the dilute solution is 0.33 L.
<u>Explanation:</u>
Using the law of Volumetric analysis, we can find the volume of the dilute solution from the stock solution or the concentrated solution of Calcium Chloride.
V1M1 = V2M2
V1 be the volume of the stock solution = 0.25 L
M1 being the molarity of the stock solution = 0.98 M
V2 be the volume of the dilute solution = ?
M2 being the molarity of the dilute solution = 0.74 M
We have to rearrange the above equation to find V2 as,
V2 = 
Now plugin the values as,
V2 = 
= 0.33 L
So the new volume of the dilute solution is 0.33 L.
Let the total mass of compound is 100g
The mass of each element will be
Al = 22.10 g
P = 25.40 g
O = 52.50 g
In order to determine the molecular formula we will calculate the molar ratio of the given elements
Atomic weight of Al : 27 g/ mol
Atomic weight of P : 3 1g /mol
Atomic weight of O : 16 g /mol
Moles of Al = mass / atomic mass = 22.10 / 27 = 0.819
Moles of P = mass / atomic mass = 25.40/ 31 = 0.819
Moles of O = mass / atomic mass = 52.50/ 16 = 3.28
Now we will divide the moles of each element with the lowest moles obtained to obtain a whole number ratio of moles of each element present
moles of Al = 0.819 / 0.819 = 1
moles of P = 0.819 / 0.819 = 1
moles of O = 3.28 / 0.819 = 4
So the empirical formula will be : AlPO4
Answer:
B. - 210 kJ
Explanation:
<em>∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.</em>
- The bond formation in the products releases energy (exothermic).
- The bond breaking in the reactants requires energy (endothermic).
The products:
- H₂O contains 2 O-H (- 459 kJ/mol) bonds.
- O₂ contain 1 O=O (- 494 kJ/mol) bond.
The reactants:
- H₂O₂ contain 2 O–H (459 kJ/mol) bonds and 1 O–O (142 kJ/mol) bond.
∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.
<em>∴ ΔHrxn = [2 (2 x (O–H bond energy) + (1 x (O=O bond energy)] - 2 [(2 x (O–H bond energy) + (1 x (O–O bond energy)] </em>= [2 (2 x - 459 kJ/mol) + (1 x - 494 kJ/mol)] - 2 [(2 x 459 kJ/mol) + (1 x 142 kJ/mol)] = (- 2330 kJ) + (2120 kJ) = <em>- 210 kJ.</em>
A la química a veces se le llama "la ciencia central", porque une la física con otras ciencias naturales, como la geología y la biología. La química es el estudio de la materia y sus propiedades.
Mi mala si esto no ayuda
