Answer:
D) Oxygen is oxidized and hydrogen is reduced.
Explanation:
In the electrolysis of water, an electric current passes through an electrolytic solution (e.g. aqueous NaCl), leading to the following redox reaction.
H₂O(l) → H₂(g) + 1/2 O₂(g)
The corresponding half-reactions are:
Reduction: 2 H₂O(l) + 2 e⁻ → H₂(g) + 2 OH⁻
Oxidation: 2 H₂O(l) → O₂(g) + 4 H⁺(aq) + 4 e⁻
As we can see, H in water is reduced (its oxidation number decreases from 1 to 0), while O in water is oxidized (its oxidation number increases from -2 to 0).
Answer:
Change in molarity, temperature, volume/pressure depending on the conditions given
Explanation:
It really depends on the type of a reaction, however, we may apply general trends and see every possibility:
- if we increase the concentration of products, then, according to the principle of Le Chatelier, the equilibrium will shift toward the formation of products;
- if we have an endothermic reaction, increasing heat will lead a shift to the right and toward formation of products, since heat might be considered a reactant as well;
- if we have an exothermic reaction, removing heat/decreasing temperature will lead to an increase in products, as we're removing one of our products, heat, and system will try to rebuild the amount of heat lost forming the other products as a result as well;
- if we have gaseous substances in a reaction, an increase in pressure will shift the equilibrium to the right if we have a greater amount in moles of reactant gases compared to products, this is also known as a decrease in volume;
- if we have gaseous substances in a reaction, a decrease in pressure will shift the equilibrium to the right if we have a greater amount in moles of product gases compared to reactants, this is also known as an increase in volume.
Answer:
0,31%
Explanation:
For the reaction:
I₂ + 2 S₂O₃²⁻ → 2 I⁻ + S₄O₆²⁻
0,043 L × 0,117 M of sodium tiosulfate = 5,031x10⁻³ moles of S₂O₃²⁻
5,031x10⁻³ moles of S₂O₃²⁻ × 
= <em>2,5156x10⁻³ moles of I₂</em>
These moles of I₂ were produced from:
ClO⁻⁻ + 2 H⁺ + 2 I⁻ → I₂ + Cl⁻ + H2O
2,5156x10⁻³ moles of I₂ ≡ moles of NaClO
2,5156x10⁻³ moles of NaClO ×
=<em> 0,187 g of NaClO</em>
Thus, percentage composition by mass is:
=<em> 0,31%</em>
I hope it helps!
The answer is the option (3) The geometric shape of a CH4 molecule
distributes the charges geometrically. the CH4 is a tetrahedral with the
Carbon atom in the center and the four H atoms in the vertices of the
tetrahedral. The C-H bond angles are all identical which makes the
molecule perfectly symmetrical and so any dipolar moment will cancel
making the molecule non polar.
Explanation:
The pKa value of acetic acid is determined experimentally by plotting pH titration curve.
The hydrogen ion, H+ concentration can be determined by performing a pH titration of a weak acid with a strong base like NaOH etc.
Starting from the dissociation equation for the acid,
HA(aq) + OH-(aq) --> H3O+(aq) + A−(aq)
we obtain for the point of half equivalence (where half of the acid has reacted with the base):
[A−] = [HA].
From the equilibrium equation
it therefore follows that
pKa = pH.
