Unlike solid matter, where particles are tightly packed and slightly vibrating, or gas, where particles go around everywhere and are extremely loose, a liquid has particles that are loosely packed but are still in slight contact with each other. Hope that's good enough
Answer :
The correct answer for primary component of phosphate buffer at pH = 7.4 is H₂PO₄⁻ and HPO₄²⁻ .
<u>Buffer solution :</u>
It is a solution of mixture of weak acid and its conjugate base OR weak base and its conjugate acid . It resist any change in solution when small amount of strong acid or base is added .
<u>Capacity of a good buffer : </u>
A good buffer is identified when pH = pKa .
From Hasselbalch - Henderson equation which is as follows :
![pH = pka + log \frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=pH%20%3D%20pka%20%2B%20log%20%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
If [A⁻] = [HA] ,
pH = pka + log 1
pH = pKa
This determines that if concentration of weak acid and its conjugate base are changed in small quantity , the capacity of buffer to maintain a constant pH is greatest at pka . If the amount of [A⁻] or [HA] is changed in large amount , the log value deviates more than +/- 1M and hence pH .
Hence Buffer has best capacity at pH = pka .
<u>Phosphate Buffer : </u>
Phosphate may have three types of acid-base pairs at different pka ( shown in image ).
Since the question is asking the pH = 7.4
At pH = 7.4 , the best phosphate buffer will have pka near to 7.4 .
If image is checked the acid - base pair " H₂PO₄⁻ and HPO₄²⁻ has pka 7.2 which is near to pH = 7.4 .
Hence we can say , the primary chemical component of phosphate buffer at pH = 7.4 is H₂PO₄⁻ and HPO₄²⁻ .
Answer:
copper metal and steel metak
Answer:
D.
Explanation:
You try to get 8 electron on the outermost "shell" so you have no left over or "valence" electrons.
<h3>
Answer:</h3>
2Fe(s) + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂(g)
<h3>
Explanation:</h3>
The equation for the reaction between iron metal and sulfuric acid is given by;
Fe(s) + H₂SO₄ → Fe₂(SO₄)₃ + H₂(g)
We are supposed to balance the equation:
What do we mean by balancing a chemical equation?
- Balancing a chemical equations means that we want to make sure the number of atoms of each element is the same on both sides of the equation.
How is balancing done?
- Balancing of chemical equations is try and error process that is done by putting appropriate coefficients on the reactants and products to equate the number of atoms of each element.
Why are subscripts on the compounds not changed?
- Subscripts in a compound show the actual number of atoms of each element in the compound and therefore can never be altered with because it will distort the chemical compound.
Why is it necessary to balance chemical equations?
- Chemical equations are balanced for them to obey the law of conservation of mass.
- According to this law, the mass of the reactants should be equal to the mass of products, which is achieved through balancing an equation.
What is the required balanced equation?
- The equation given can be balanced by putting the coefficients 2, 3, 1, 3 in that order on the reactants and products.
- Therefore, the balanced chemical equation is;
2Fe(s) + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂(g)
