Nucleolus what is a nucleolus

Which statement is FALSE? a. ΔHrxn is the heat of reaction. b. ΔErxn is a measure of heat. c. An exothermic reaction gives heat

Pavlova-9 [17]

Answer:

b. ΔE rxn is a measure of heat

Explanation:

a. ΔHrxn is the heat of reaction. TRUE. ΔHrxn or change in enthalpy of reaction is per definition the change in heat that is involved in a chemical reaction.

b. ΔErxn is a measure of heat. FALSE. Is the change in internal energy of a reaction

c. An exothermic reaction gives heat off heat to the surroundings. TRUE. An exothermic reaction is a chemical reaction that releases heat.

d. Endothermic has a positive ΔH. TRUE. When a process is exothermic ΔH<0 and when the process is endothermic ΔH>0

e. Enthalpy is the sum of a system's internal energy and the product of pressure and volume. TRUE. Under constant pressure and volume the formula is ΔH = ΔE + PV

I hope it helps!

3 0

3 years ago

Solid Magnesium reacts with a Iron (II) Chloride solution ->

photoshop1234 [79]

Answer:

Magnesium + iron chloride → iron + magnesium chloride

Explanation:

It is the single replacement reaction.

Single replacement:

It is the reaction in which one elements replace the other element in compound.

AB + C → AC + B

Molecular equation:

Magnesium + iron chloride → iron + magnesium chloride

Chemical equation:

Mg(s) + FeCl₂(aq) → MgCl₂(aq) + Fe(s)

Ionic equation:

Mg(s) + Fe²⁺(aq) + 2Cl⁻(aq) → Mg²⁺(aq) + 2Cl⁻(aq) + Fe(s)

Net ionic equation:

Mg(s) + Fe²⁺(aq) → Fe(s) + Mg²⁺(aq)

5 0

3 years ago

2. STEM The mass of an atom of helium is about 4.002 atomic units.

Anit [1.1K]

Answer:

The approximate mass of beryllium is 9.0045 u.

Explanation:

Given data:

mass of helium= 4.002 u

mass of beryllium which is 2.25 times of mass of helium= ?

Solution:

we will multiply the mass of helium with 2.25 times,

4.002 u × 2.25 = 9.0045 u

so the mass of beryllium atom would be 9.0045 u.

6 0

3 years ago

Combine the two half-reactions that give the spontaneous cell reaction with the smallest E∘. Fe2+(aq)+2e−→Fe(s) E∘=−0.45V I2(s)+

Iteru [2.4K]

Answer: The spontaneous cell reaction having smallest $E^o$ is $I_2+Cu\rightarrow Cu^{2+}+2I^-$

Explanation:

We are given:

$E^o_{(Fe^{2+}/Fe)}=-0.45V\\E^o_{(I_2/I^-)}=0.54V\\E^o_{(Cu^{2+}/Cu)}=0.34V$

The substance having highest positive $E^o$ potential will always get reduced and will undergo reduction reaction. Here, iodine will always undergo reduction reaction, then copper and then iron.

The equation used to calculate electrode potential of the cell is:

$E^o_{cell}=E^o_{oxidation}+E^o_{reduction}$

The combination of the cell reactions follows:

Case 1:

Here, iodine is getting reduced and iron is getting oxidized.

The cell equation follows:

$I_2(s)+Fe(s)\rightarrow Fe^{2+}(aq.)+2I^-(aq.)$

Oxidation half reaction: $Fe(s)\rightarrow Fe^{2+}(aq.)+2e^-$ $E^o_{oxidation}=0.45V$

Reduction half reaction: $I_2(s)+2e^-\rightarrow 2I_-(aq.)$ $E^o_{reduction}=0.54V$

$E^o_{cell}=0.45+0.54=0.99V$

Thus, this cell will not give the spontaneous cell reaction with smallest $E^o_{cell}$

Case 2:

Here, iodine is getting reduced and copper is getting oxidized.

The cell equation follows:

$I_2(s)+Cu(s)\rightarrow Cu^{2+}(aq.)+2I^-(aq.)$

Oxidation half reaction: $Cu(s)\rightarrow Cu^{2+}(aq.)+2e^-$ $E^o_{oxidation}=-0.34V$

Reduction half reaction: $I_2(s)+2e^-\rightarrow 2I_-(aq.)$ $E^o_{reduction}=0.54V$

$E^o_{cell}=-0.34+0.54=0.20V$

Thus, this cell will give the spontaneous cell reaction with smallest $E^o_{cell}$

Case 3:

Here, copper is getting reduced and iron is getting oxidized.

The cell equation follows:

$Cu^{2+}(aq.)+Fe(s)\rightarrow Fe^{2+}(aq.)+Cu(s)$

Oxidation half reaction: $Fe(s)\rightarrow Fe^{2+}(aq.)+2e^-$ $E^o_{oxidation}=0.45V$

Reduction half reaction: $Cu^{2+}(aq.)+2e^-\rightarrow Cu(s)$ $E^o_{reduction}=0.34V$

$E^o_{cell}=0.45+0.34=0.79V$

Thus, this cell will not give the spontaneous cell reaction with smallest $E^o_{cell}$

Hence, the spontaneous cell reaction having smallest $E^o$ is $I_2+Cu\rightarrow Cu^{2+}+2I^-$

7 0

3 years ago

Which family of the periodic table forms ions with a -1 charge

Anon25 [30]

Answer:

ur mom

sorry I had to :(((

5 0

3 years ago

Nucleolus what is a nucleolus​

Nucleolus what is a nucleolus