Answer:
0.102 mol
Explanation:
Step 1: Write the balanced equation
PCl₅ + 4 H₂O ⇒ 5 HCl + H₃PO₄
Step 2: Calculate the moles corresponding to 7.36 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
7.36 g × 1 mol/18.02 g = 0.408 mol
Step 3: Calculate the moles of PCl₅ required to react with 0.408 moles of H₂O
The molar ratio of PCl₅ to H₂O is 1:4.
0.408 mol H₂O × 1 mol PCl₅/4 mol H₂O = 0.102 mol PCl₅
Answer:
k = -0.09165 years^(-1)
Explanation:
The exponential decay model of a radioactive isotope is generally given as;
A(t) = A_o(e^(kt))
Where;
A_o is quantity of isotope before decay, k is decay constant and A(t) is quantity after t years
We are given;
A_o = 5 kg
A(10) = 2kg
t = 10 years
Thus;
A(10) = 2 = 5(e^(10k))
Thus;
2 = 5(e^(10k))
2/5 = (e^(10k))
0.4 = (e^(10k))
In 0.4 = 10k
-0.9164 = 10k
k = -0.9164/10
k = -0.09165 years^(-1)
Hello!
A solution of a weak acid and its conjugate base is called a
buffer solution. It can resist the addition of bases and acids while maintaining the pH approximately constant.
To calculate the pH of a buffer solution, we'll use the famous Henderson-Hasselbach equation, applying the pKa value of the Benzoic Acid (4,20). In this equation, [A⁻] represents the concentration of the Conjugate Base and [HA] the concentration of the acid.
![pH=pKa + log( \frac{ [A^{-}]}{[HA]} ) \\ \\ pH=4,20 + log ( \frac{0,170 M}{0,245} ) \\ \\ pH=4,04](https://tex.z-dn.net/?f=pH%3DpKa%20%2B%20log%28%20%5Cfrac%7B%20%5BA%5E%7B-%7D%5D%7D%7B%5BHA%5D%7D%20%29%20%5C%5C%20%20%5C%5C%20pH%3D4%2C20%20%2B%20log%20%28%20%5Cfrac%7B0%2C170%20M%7D%7B0%2C245%7D%20%29%20%5C%5C%20%20%5C%5C%20pH%3D4%2C04%20)
So, the pH of the solution would be
4,04.Have a nice day!
Answer:
Mass of Fe = 32.55 g
Explanation:
Molar Mass of Fe atom = 55.845 g/mol
It means,
1 mole of Fe contains = 55.845 g ..............(1)
From mole concept,
<u>1 mole </u>of Fe contain =
atom ..........(2)
Replace 1 mole in equation (2) by 55.845 g , it become :
55.845 g of Fe contain =
atoms
Reverse the equation now
atoms of Fe contain =55.845 g
1 atom of Fe contain =
g
atom contain =

on calculation,
atom contain = 32.55 g of Fe
Mass of Fe = 32.55 g