Which statement describes a digital signal?

Which one of the following atoms has the largest radius? Ова Осо OCa

RUDIKE [14]

Answer:

Ba

Explanation:

<u>The elements Calcium ( Ca ) and Cobalt ( Co ) , are both present in the same period , and across the period the atomic radius decreases from left to right , since , the atomic number increases , so the electrons increases , which in turns increases the effective nuclear charge , and hence the size decreases , </u>

Therefore ,

Calcium will have bigger atomic radii as compared to Cobalt .

Now,

<u>The elements Barium ( Ba ) and Calcium ( Ca ) are , both are present in the same group , and down the group , atomic radii increases , since , as going down the group , the atomic number increase , so the shells increases , hence the size increases .</u>

Therefore , the atom with the largest radii is Barium .

7 0

3 years ago

Consider the reaction of metallic copper with iron(!!) to give copper(ll) and ironin 0.77V Fe* (aq) + e-Fe (aq) Cup (aq) + 2e --

frosja888 [35]

Answer :

(a) The anode and cathode will be $E^o_{(Cu^{2+}/Cu)}$

and $E^o_{(Fe^{3+}/Fe^{2+})}$ respectively.

(b) The emf of cell potential is 1.022 V

Explanation :

(a) The standard reduction potentials for iron and copper are:

$E^o_{(Fe^{3+}/Fe^{2+})}=0.77V\\E^o_{(Cu^{2+}/Cu)}=0.34V$

In the voltaic cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode.

From the standard reduction potentials we conclude that, the substance having highest positive $E^o$ potential will always get reduced and will undergo reduction reaction.

So, iron will undergo reduction reaction will get reduced. Copper will undergo oxidation reaction and will get oxidized.

The given cell reactions are:

Oxidation half reaction (anode): $Cu\rightarrow Cu^{2+}+2e^-$

Reduction half reaction (cathode): $Fe^{3+}+1e^-\rightarrow Fe^{2+}$

Thus, the anode and cathode will be $E^o_{(Cu^{2+}/Cu)}$

and $E^o_{(Fe^{3+}/Fe^{2+})}$ respectively.

(b) Now we have to calculate the potential of a cell.

Oxidation half reaction (anode): $Cu\rightarrow Cu^{2+}+2e^-$

Reduction half reaction (cathode): $Fe^{3+}+1e^-\rightarrow Fe^{2+}$

In order to balance that electrons, we will multiple the reduction reaction by 2, we get:

Oxidation half reaction (anode): $Cu\rightarrow Cu^{2+}+2e^-$

Reduction half reaction (cathode): $2Fe^{3+}+2e^-\rightarrow 2Fe^{2+}$

The overall cell reaction will be,

$2Fe^{3+}+Cu\rightarrow Cu^{2+}+2Fe^{2+}$

$E^o_{[Fe^{3+}/Fe^{2+}]}=2\times 0.77V=1.54V$

$E^o_{[Cu^{2+}/Cu]}=0.34V$

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

$E^o=E^o_{[Fe^{3+}/Fe^{2+}]}-E^o_{[Cu^{2+}/Cu]}$

$E^o=1.54V-(0.34V)=1.20V$

Now we have to calculate the cell potential.

Using Nernest equation :

$E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Fe^{2+}]^2[Cu^{2+}]}{[Fe^{3+}]^2}$

where,

n = number of electrons in oxidation-reduction reaction = 2

$E_{cell}$ = emf of the cell = ?

Now put all the given values in the above equation, we get:

$E_{cell}=1.20-\frac{0.0592}{2}\log \frac{(0.20)^2(0.25)}{(0.0001)^2}$

$E_{cell}=1.022V$

Therefore, the emf of cell potential is 1.022 V

5 0

3 years ago

Compare and contrast physical property and chemical property

amm1812

Physical properties are properties that change form but not it's chemical compound

chemical properties are properties that change in chemical substance like burning tearing

3 0

3 years ago

Use the bond energy to calculate an approximate value of δh for the following reaction. Which is the more stable form of fno2?

professor190 [17]

The enthalpy of reaction or ∆H reaction is the difference between the bond energy of the reactants and the bond energy of the products.

<h3>What is ∆H reaction?</h3>

The term ∆H reaction refers to the heat that is evolved or absorbed in a chemical reaction. It is also known as the enthalpy of reaction.

The question is incoherent but I will try to answer as much as possible. Using the values of bond energy, ∆H reaction = Bond energy of reactants - bond energy of products. This will give us the enthalpy of reaction.

Learn more about bond energy: brainly.com/question/1657608

8 0

2 years ago

Which would increase the reaction rate?

murzikaleks [220]

Answer:

C. Adding a catalyst

Explanation:

Because the catalyst increases the rate of chemical reaction

8 0

3 years ago