Answer:
ΔHreaction = 263.15 kJ/mol
Explanation:
The reaction is as follow:
OH + CF₂Cl₂ → HOF + CFCl₂
You need to calculate the enthalpy of reaction and for this it is necessary to know the standard enthalpies for each of the compounds. These enthalpies are as follows and can be found in your textbook or on the Internet.
ΔHreaction = ∑ΔHproducts - ∑ΔHreactants

Given :
Number of molecules of hydrogen peroxide, N = 4.5 × 10²².
To Find :
The mass of given molecules of hydrogen peroxide.
Solution :
We know, 1 mole of every compound contains Nₐ = 6.022 × 10²³ molecules.
So, number of moles of hydrogen peroxide is :

Now, mass of hydrogen peroxide is given as :
m = n × M.M
m = 0.0747 × 34 grams
m = 2.54 grams
Hence, this is the required solution.
Density = mass / volume
D = 550 / 25
D = 22 g/mL
hope this helps!
<u>Answer:</u> The mass of second isotope of indium is 114.904 amu
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
Let the mass of isotope 2 of indium be 'x'
Mass of isotope 1 = 112.904 amu
Percentage abundance of isotope 1 = 4.28 %
Fractional abundance of isotope 1 = 0.0428
Mass of isotope 2 = x amu
Percentage abundance of isotope 2 = [100 - 4.28] = 95.72 %
Fractional abundance of isotope 2 = 0.9572
Average atomic mass of indium = 114.818 amu
Putting values in equation 1, we get:
![114.818=[(112.904\times 0.0428)+(x\times 0.9572)]\\\\x=114.904amu](https://tex.z-dn.net/?f=114.818%3D%5B%28112.904%5Ctimes%200.0428%29%2B%28x%5Ctimes%200.9572%29%5D%5C%5C%5C%5Cx%3D114.904amu)
Hence, the mass of second isotope of indium is 114.904 amu
Answer:
Molarity of acid, Ca = Cb*Vb*A/Va*B
Explanation:
Using H2SO4 as acid, the reaction is as follow:
2NaOH + H2SO4 ⇒ Na2SO4 + 2H2O
Volume of acid = Va; Volume of base = Vb, Molar concentration of acid = Ca; Molar concentration of base = Cb; Molarity of acid = A and Molarity of base = B
Ca*Va/Cb*Vb =A/B
∴ Ca = Cb*Vb*A/Va*B