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3 years ago

Standard hydrogen electrode acts as both anode and cathode.Explain.

Chemistry

2 answers:

Vlad [161]3 years ago

8 0

Answer:

A Standard Hydrogen Electrode is an electrode that scientists use for reference on all half-cell potential reactions. The value of the standard electrode potential is zero, which forms the basis one needs to calculate cell potentials using different electrodes or different concentrations. It is important to have this common reference electrode, just as it is important for the International Bureau of Weights and Measures to keep a sealed piece of metal that is used to reference the S.I. Kilogram.

AnnZ [28]3 years ago

7 0

Answer:

The role of an electrode as cathode or anode depends on the nature and electrode potential of the other electrode with which it forms the complete electrochemical cell.

When a cell is to be made with zinc electrode and hydrogen electrode, the hydrogen electrode will behave as a cathode and the zinc electrode will behave as anode because zinc is present above hydrogen in the activity series. That is zinc is more electropositive than hydrogen.

If the cell is made with a copper electrode and hydrogen electrode, the hydrogen electrode will behave as anode and the copper electrode as a cathode. This is due to the fact that Cooper is present below hydrogen in the activity series. Copper is less electropositive than hydrogen.

Explanation:

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The solubility of CaSO4 in pure water at 0oC is 1.09 gram(s) per liter. The value of the solubility product is g

malfutka [58]

Answer: See image attached!

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3 years ago

"An aqueous CaCl2 solution has a vapor pressure of 83.1mmHg at 50 ∘C. The vapor pressure of pure water at this temperature is 92

Lynna [10]

Answer : The the concentration of $CaCl_2$ in mass percent is, 41.18 %

Solution : Given,

Molar mass of water = 18 g/mole

Molar mass of $CaCl_2$ = 110.98 g/mole

First we have to calculate the mole fraction of solute.

According to the relative lowering of vapor pressure, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component of the solution multiplied by the vapor pressure of that component in the pure state.

$\fac{p^o-p_s}{p^o}=X_B$

where,

$p^o$ = vapor pressure of the pure component (water) = 92.6 mmHg

$p_s$ = vapor pressure of the solution = 83.1 mmHg

$X_B$ = mole fraction of solute, $(CaCl_2)$

Now put all the given values in this formula, we get the mole fraction of solute.

$\fac{92.6-83.1}{92.6}=X_B$

$X_B=0.102$

Now we have to calculate the mole fraction of solvent (water).

As we know that,

$X_A+X_B=1\\\\X_A=1-X_B\\\\X_A=1-0.102\\\\X_A=0.898$

The number of moles of solute and solvent will be, 0.102 and 0.898 moles respectively.

Now we have to calculate the mass of solute, $(CaCl_2)$ and solvent, $(H_2O)$ .

$\text{Mass of }CaCl_2=\text{Moles of }CaCl_2\times \text{Molar mass of }CaCl_2$

$\text{Mass of }CaCl_2=(0.102mole)\times (110.98g/mole)=11.32g$

$\text{Mass of }H_2O=\text{Moles of }H_2O\times \text{Molar mass of }H_2O$

$\text{Mass of }H_2O=(0.898mole)\times (18g/mole)=16.164g$

Mass of solution = Mass of solute + Mass of solvent

Mass of solution = 11.32 + 16.164 = 27.484 g

Now we have to calculate the mass percent of $CaCl_2$

$Mass\%=\frac{\text{Mass of}CaCl_2}{\text{Mass of solution}}\times 100=\frac{11.32g}{27.484g}\times 100=41.18\%$

Therefore, the the concentration of $CaCl_2$ in mass percent is, 41.18 %

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3 years ago

Write a balanced equation for the oxidation-reduction reaction that occurs when hydrogen peroxide reacts with ferrous ion

Alex17521 [72]

H₂O₂ + 2FeSO₄ + H₂SO₄ → Fe₂(SO₄)₃ + 2H₂O

H₂O₂ + 2H⁺ + 2e⁻ → 2H₂O k=1
Fe²⁺ → Fe³⁺ + e⁻ k=2

H₂O₂ + 2H⁺ + 2Fe²⁺ → 2H₂O + 2Fe³⁺

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3 years ago

Why do atoms always contain the same number of electrons and protons?

katovenus [111]

Answer:

An electron is a negatively charged subatomic particle and a proton is a positively charged subatomic particle. Positive charge(s) attract negative charge(s) and vice versa. The proton and neutron stay together and attract one another to give the atom an overall charge of zero (neutral). Which is the charge of an atom. When there is an unequal number of protons and neutrons an ion is formed. If the number of protons are more than the electron, a positively charged ion called cation is formed. On the other hand, if the number of electrons are more than the protons a negatively charged ion called anion is formed.

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3 years ago

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In the reaction catalyzed by the pyruvate dehydrogenase complex, the two carbons constituting the acetyl group are

lara [203]

Transferred to the lipoamide by an earlier intermediate in the process.

The pyruvate dehydrogenase complex (PDC) is a mitochondrial multienzyme complex composed of three different enzymes

<h3>What reaction is catalyzed by enzyme 2 of the pyruvate dehydrogenase complex ?</h3>

the pyruvate dehydrogenase complex is the bridge between glycolysis and the citric acid cycle

Five coenzymes are used in the pyruvate dehydrogenase complex reactions: thiamine pyrophosphate or TPP, flavin adenine dinucleotide or FAD, coenzyme A or CoA, nicotinamide adenine dinucleotide or NAD, and lipoic acid.
during the reactions catalyzed by the pyruvate dehydrogenase complex, it is first reduced to dihydrolipoamide, a dithiol or the reduced form of the prosthetic group, and then, reoxidized to the cyclic form.

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2 years ago

Standard hydrogen electrode acts as both anode and cathode.Explain.​

Standard hydrogen electrode acts as both anode and cathode.Explain.