The number of oxygen atoms that are in 4 Al₂O₃ are 12 atoms
<u><em> Explanation</em></u>
- The subscript in a chemical formula indicate the number of atoms of element immediately before the subscript.
- coefficient is the number in front of the formula and tells us how many molecules of a given formula are present.
- Since 4Al₂O₃ has coefficient of 4 and the subscript of O is 3 the number of O atoms = 4 x 3=12 atoms
Answer:
Explanation:
From the given information:
A → B k₁
B → A k₂
B + C → D k₃
The rate law = ![\dfrac{d[D]}{dt}=k_3[B][C] --- (1)](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BD%5D%7D%7Bdt%7D%3Dk_3%5BB%5D%5BC%5D%20---%20%281%29)
![\dfrac{d[B]}{dt}=k[A] -k_2[B] -k_3[B][C]](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BB%5D%7D%7Bdt%7D%3Dk%5BA%5D%20-k_2%5BB%5D%20-k_3%5BB%5D%5BC%5D)
Using steady-state approximation;
![\dfrac{d[B]}{dt}=0](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BB%5D%7D%7Bdt%7D%3D0)
![k_1[A]-k_2[B]-k_3[B][C] = 0](https://tex.z-dn.net/?f=k_1%5BA%5D-k_2%5BB%5D-k_3%5BB%5D%5BC%5D%20%3D%200)
![[B] = \dfrac{k_1[A]}{k_2+k_3[C]}](https://tex.z-dn.net/?f=%5BB%5D%20%3D%20%5Cdfrac%7Bk_1%5BA%5D%7D%7Bk_2%2Bk_3%5BC%5D%7D)
From equation (1), we have:
![\mathbf{\dfrac{d[D]}{dt}= \dfrac{k_3k_1[A][C]}{k_2+k_3[C]}}](https://tex.z-dn.net/?f=%5Cmathbf%7B%5Cdfrac%7Bd%5BD%5D%7D%7Bdt%7D%3D%20%5Cdfrac%7Bk_3k_1%5BA%5D%5BC%5D%7D%7Bk_2%2Bk_3%5BC%5D%7D%7D)
when the pressure is high;
k₂ << k₃[C]
![\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_3[C]}= k_1A \ \ \text{first order}](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BD%5D%7D%7Bdt%7D%20%3D%20%5Cdfrac%7Bk_3k_1%5BA%5D%5BC%5D%7D%7Bk_3%5BC%5D%7D%3D%20k_1A%20%5C%20%5C%20%20%5Ctext%7Bfirst%20order%7D)
k₂ >> k₃[C]
![\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_2}= \dfrac{k_1k_3}{k_2}[A][C] \ \ \text{second order}](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BD%5D%7D%7Bdt%7D%20%3D%20%5Cdfrac%7Bk_3k_1%5BA%5D%5BC%5D%7D%7Bk_2%7D%3D%20%5Cdfrac%7Bk_1k_3%7D%7Bk_2%7D%5BA%5D%5BC%5D%20%5C%20%5C%20%20%5Ctext%7Bsecond%20order%7D)
If Ka for HCN is 6. 2×10^−10 at 25 °C, then the value of Kb for cn− at 25 °C is 1.6 × 10^(-5).
<h3>What is base dissociation constant? </h3><h3 />
The base dissociation constant (Kb) is defined as the measurement of the ions which base can dissociate or dissolve in the aqueous solution. The greater the value of base dissociation constant greater will be its basicity an strength.
The dissociation reaction of hydrogen cyanide can be given as
HCN --- (H+) + (CN-)
Given,
The value of Ka for HCN is 6.2× 10^(-10)
The correlation between base dissociation constant and acid dissociation constant is
Kw = Ka × Kb
Kw = 10^(-14)
Substituting values of Ka and Kw,
Kb = 10^(-14) /{6.2×10^(-10) }
= 1.6× 10^(-5)
Thus, the value of base dissociation constant at 25°C is 1.6 × 10^(-5).
learn more about base dissociation constant :
brainly.com/question/9234362
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add all the number and find the average then subtract the mass defect and then you will get your answer
Answer:
Take 100 ml of a 18 molar solution. The total number of moles is (1 liter/1000 ml) 100 ml 18 moles is 1.8 moles.
1.5 moles in 1 liter so If 1.1 liters of water is added, the total volume is 1.2 liters and 1.8 moles are dissolves in it. 1.8 moles/ 1.2 liters is 1.5 moles per liter.
