Answer:
For disodium hydrogen phosphate:
5.32g Na2HPO4
For sodium dihydrogen phosphate:
7.65g Na2HPO4
Explanation:
First, you have to put all the data from the problem that you going to use:
-NaH2PO4 (weak acid)
-Na2HPO4 (a weak base)
-Volume = 1L
-Buffer pH = 7.00
-Concentration of [NaH2PO4 + Na2HPO4] = 0.100 M
What we need to find the pKa of the weak acid, in this case NaH2PO4, for that you need to find the Ka (acid constant) of NaH2PO4, and for this we use the pKa of the phosphoric acid as follow:
H3PO4 = H2PO4 + H+ pKa1 = 2.14
H2PO4 = HPO4 + H+ pKa2 = 6.86
HPO4 = PO4 + H+ pKa3 = 12.4
So, for the preparation of buffer, you need to use the pKa that is near to the value of the pH that you want, so the choice will be:
pKa2= 6.86
Now we going to use the Henderson Hasselbalch equation for the pH of a buffer solution:
pH = pKa2 + log [(NaH2PO4)/(Na2HPO4)]
The solution of the problem is attached to this answer.
In diesel engines, the chemical energy in the fuel is changed to heat energy, causing the pistons to expand via mechanical energy. The mechanical energy is finally converted to kinetic energy, which is observed as the movement of the vehicle.
Answer:
It favors the forward reaction.
Explanation:
According to Le Chatelier's Principle, when a system at equilibrium suffers a perturbation, the system will react in order to counteract the effect of such perturbation.
If more reactant is added, the system will try to decrease its concentration. It will do so by favoring the forward reaction, decreasing the concentration of the reactant and increasing the concentration of the products, in order to re-establish the equilibrium.
Decomposition reaction D. 2H20⇒ 2H2 + O2
<h3>Further explanation
</h3>
Every chemical reaction involves a compound consisting of reactants and products
Reactants are compounds that react and form new compounds called products
There are several forms of reactions that can occur, including single replacement, double replacement, synthesis, decomposition, etc.
A. 2C2H6 + 702 ⇒ 4CO2 + 6H20
Combustion : reaction of Hydrocarbon and Oxygen
B. AgNO3 + LiCl → AgCl + LINO3
Double replacement : there is an ion exchange between two ion compounds in the reactant to form two new ion compounds in the product
C. Ca + MgS → CaS + Mg
Single replacement :one element replaces the other elements of a compound to produce new elements and compounds
D. 2H20⇒ 2H2 + O2
Decomposition : One compound breaks down into 2 components
Answer:
A
Explanation:
Molecules of a gas are relatively more compressible than those of liquids and solids because they are relatively far apart without any intermolecular forces between them. However, at lower temperature and higher pressure, there is now a significant intermolecular interaction between the gas molecules and they are no longer relatively far apart. Hence they are more compressible than liquids and solids which already possess significant intermolecular interaction and thus a definite volume.
