Answer:
ΔpH = 0.20
Explanation:
The buffer of HCO₃⁻ + CO₃²⁻ has a pka of 10.2
HCO₃⁻ ⇄ H⁺ + CO₃²⁻
There are 0.479moles of NaHCO₃ and 0.342moles of Na₂CO₃.
Using Henderson-Hasselbalch formula:
pH = pka + log [Base] / [Acid]
pH = 10.2 + log 0.342mol / 0.479mol
<em>pH = 10.05</em>
NaOH reacts with HCO₃⁻ producing CO₃²⁻, thus:
NaOH + HCO₃⁻ → CO₃²⁻ + H₂O + Na⁺
0.091 moles of NaOH produce the same moles of CO₃²⁻ and consume HCO₃⁻. Moles of these species are:
CO₃²⁻: 0.342mol + 0.091mol: 0.433mol
HCO₃⁻: 0.479mol - 0.091 mol: 0.388mol
Using Henderson-Hasselbalch formula:
pH = pka + log [Base] / [Acid]
pH = 10.2 + log 0.433mol / 0.388mol
pH = 10.25
That means change of pH, ΔpH is:
ΔpH = 10.25 - 10.05 = <em>0.20</em>
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I hope it helps!
Answer:Scientific literacy is the knowledge and understanding of scientific concepts and processes required for personal decision making, participation in civic and cultural affairs, and economic productivity. It also includes specific types of abilities.Science literacy is important because it provides a context for addressing societal problems, and because a science- literate populace can better cope with many of its prob- lems and make intelligent and informed decisions that will affect the quality of their lives and those of their children.
Explanation:
Answer:
Aluminum metal
Explanation:
In order to properly answer this or a similar question, we need to know some basic rules about galvanic cells and standard reduction potentials.
First of all, your strategy would be to find a trusted source or the table of standard reduction potentials. You would then need to find the half-equations for aluminum and gold reduction:
Since we have a galvanic cell, the overall reaction is spontaneous. A spontaneous reaction indicates that the overall cell potential should be positive.
Since one half-equation should be an oxidation reaction (oxidation is loss of electrons) and one should be a reduction reaction (reduction is gain of electrons), one of these should be reversed.
Thinking simply, if the overall cell potential would be obtained by adding the two potentials, in order to acquite a positive number in the sum of potentials, we may only reverse the half-equation of aluminum (this would change the sign of E to positive):
Notice that the overall cell potential upon summing is:
Meaning we obey the law of galvanic cells.
Since oxidation is loss of electrons, notice that the loss of electrons takes place in the half-equation of aluminum: solid aluminum electrode loses 3 electrons to become aluminum cation.
Answer:
SO2
Explanation:
Dipole-Dipole exist between parmanent dipoles in a molecule. THis means that molecule must have a parmanent dipole moment in it.
Example - HCl
Hydrogen bonding is an attraction between lone pair of an electronegative element and H atom of same or different molecule. H must be covalantly attached to either F, N or O.
Example - H2O
Among the molecules given in the list only SO2 and H2O exihibits parmanent moment. As BCl3 , CBr4 and H2 are symmetric compounds.
Since, SO2 cannot exihibit H- bonding only dipole-dipole forces as its strongest intermolecular force.
The elements that apply are argon, neon and helium. These elements are called inert gasses and have unique properties that make them unreactive. These elements are so unreactive that they are classified as chemically inert.
The elements belong to a group in the periodic table known as the Noble Gases. They belong to family 18 of the periodic table and have atoms with 8 valence electrons. This configuration causes the gases to be unreactive.
