Answer:
The total energy change, ΔE, in kilojoules = -61.93 kJ
Explanation:
Relationship between ΔH, ΔE and work done is given by first law of thermodynamics.
ΔE = ΔH - PΔV
Where,
ΔH = Change in enthalpy
ΔE = Change in internal energy
PΔV = Work done
Given that,
ΔH = -75.0 kJ = -75000 J
P = 43.0 atm
ΔV = Final volume - initial volume
= (2.00 - 5.00) = -3.00 L
PΔV = 43 × (-3.00) = -129 L atm
1 L atm = 101.325 J
-129 L atm = 129 × 101.325 = -13071 J
So ,
ΔE = ΔH - PΔV
= (-75000 J) - ( -13071 J)
= -75000 J + 13071 J
= -61929 J
Total energy change, ΔE = -61.929 kJ
Answer:
250cm³ de disolución se deben preparar
Explanation:
El porcentaje volumen volumen (%v/v) se define como el volumen de soluto -En este caso, H2O2- en 100cm³ de disolución.
Se desea preparar una solución que contenga 20cm³ de H2O2 por cada 100cm³
Como solamente se cuenta con 50cm³ de H2O2, el volumen que se debe preparar es:
50cm³ H2O2 * (100cm³ Disolución / 20cm³ H2O2) =
<h3>250cm³ de disolución se deben preparar</h3>
Answer : The correct answer is, (c) the number of neutrons
Explanation :
Isotope : It is defined as the element that have the same number of protons but have the different number of neutrons of each of the atom.
Atomic number is defined as the number of protons or number of electrons.
Atomic number = number of protons = number of electrons
Mass number is defined as the sum of number of protons and number of neutrons.
Number of neutrons = Mass number - Atomic number
For example : For Carbon - 13 isotope.
Mass number = 13
Atomic number = 6
Number of neutrons = Mass number - Atomic number
Number of neutrons = 13 - 6 = 7
Hence, the difference between the mass number of an isotope and its atomic number is the number of neutrons.
Question 1
Fe(III) forms a chelate complex with salicylic acid which has purple color. therefore, when a solution is made either with salicylic acid or with aspirin having trae amount of salicylic acid in it, we see color formation in solution due to the resulting complex formed.
Question 2
The Fe(III) itself absorbs some light and gives an absorbance value for the solution. Therefore, it is necessary to blank the spectrophotometer with a Fe(III) solution prior to measurement of test solutions.
Question:
A) 12
B) 29
C) 2.1 × 10⁻²
D) 8.7 × 10⁻²
E) 47
Answer:
The correct option is;
E) 47
Explanation:
Kc, which is the equilibrium constant of a chemical reaction is derived by finding the ratio between the product of the equilibrium concentration of the product raised to their respective coefficients to the product of the equilibrium concentration of the reactants also raised to their respective coefficients.
Here we have;
[H₂] = 0.14 M
[Cl₂] = 0.39 M
[HCl] = 1.6
The reaction is given as follows;
H₂ (g) + Cl₂ (g) ⇄ 2HCl (g)
The formula for Kc is given as follows;
![Kc = \frac{[HCl]^2}{[H_2][Cl_2]} = \frac{1.6^2}{0.14 \times 0.39} = 46.886](https://tex.z-dn.net/?f=Kc%20%3D%20%5Cfrac%7B%5BHCl%5D%5E2%7D%7B%5BH_2%5D%5BCl_2%5D%7D%20%3D%20%5Cfrac%7B1.6%5E2%7D%7B0.14%20%5Ctimes%200.39%7D%20%20%3D%2046.886)
Therefore, the Kc for the reaction is approximately equal to 47.