Ca(s) + O2(g) - O A. Cao(s) B. Ca2O(s) O C. 2Ca(s) + O2(g) O D. CaO2(s)

What is the enthalpy of the overall chemical reaction ch4(g)+4cl2(g)- ccl4(g)+4hcl(g)?

Brut [27]

Answer:

-205.7kj

Explanation:

Now adding reaction 2 and twice of reaction 3 and reverse of reaction 1, we get the enthalpy of the reaction.

The expression for enthalpy for the following reaction will be,

where,

n = number of moles

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

Therefore, the enthalpy of the following reaction is, -205.7kj

4 0

3 years ago

What is the voltage of the voltaic cell Zn|Zn2+||Cu2+|Cu at 298 K if [Zn2+] = 0.2 M and [Cu2+] = 4.0 M? Cu2+ + 2e- → Cu Eo = +0.

OLga [1]

Answer : The voltage of the voltaic cell is 1.14 V

Explanation :

From the given cell representation, we conclude that

The copper will undergo reduction reaction will get reduced. Zinc will undergo oxidation reaction and will get oxidized.

The oxidation-reduction half cell reaction will be,

Oxidation half reaction: $Zn\rightarrow Zn^{2+}+2e^-$

Reduction half reaction: $Cu^{2+}+2e^-\rightarrow Cu$

Oxidation reaction occurs at anode and reduction reaction occurs at cathode. That means, gold shows reduction and occurs at cathode and chromium shows oxidation and occurs at anode.

The overall balanced equation of the cell is,

$Zn+Cu^{2+}\rightarrow Zn^{2+}+Cu$

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

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

$E^o_{cell}=E^o_{(Cu^{2+}/Cu)}-E^o_{(Zn^{2+}/Zn)}$

Putting values in above equation, we get:

$E^o_{cell}=(+0.34V)-(-0.76V)$

$E^o_{cell}=1.1V$

Now we have to calculate the emf or voltage of the cell.

Using Nernest equation at 298 K :

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

where,

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

$E_{cell}$ = ?

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

$E_{cell}=1.1-\frac{0.0592}{2}\log \frac{0.2}{4.0}$

$E_{cell}=1.14V$

Therefore, the voltage of the voltaic cell is 1.14 V

5 0

2 years ago

For a representative element, the row number on the periodic chart will be the same as the shell number. TRUE OR FALSE

OLEGan [10]

True. Row number on the periodic chart will be the same as the shell number.

8 0

3 years ago

An adult with the flu has a temperature of 102°F. Express your answer as an integer.

Pie

Answer: A integer is a whole number.

An adult with the flu has a temperature of 102°F

A brain contains neurons (moving the decimal point to the right side power of 10 increases........here decimal point is moved to two places to the right side so power of 10 decreases from 10 to 8)

The time for a nerve impulse to travel from the feet to the brain is s. (moving the decimal point to the right side power of 10 increases........here decimal point is moved to two places to the right side so power of 10 decreases from 0 to -2)

Explanation:

i hope this answer your question if this is wrong or correct please let me know

5 0

2 years ago

What are two examples of a soulution?

Anni [7]

Which type of solution are you talking about?

3 0

3 years ago