Scientific Inquiry begins with?

Calculate the standard reaction Gibbs free energy for the following cell reactions: (a) 2 Ce41(aq) 1 3 I2(aq) S 2 Ce31(aq) 1 I32

Law Incorporation [45]

Answer:

For a: The standard Gibbs free energy of the reaction is -347.4 kJ

For b: The standard Gibbs free energy of the reaction is 746.91 kJ

Explanation:

Relationship between standard Gibbs free energy and standard electrode potential follows:

$\Delta G^o=-nFE^o_{cell}$ ............(1)

For a:

The given chemical equation follows:

$2Ce^{4+}(aq.)+3I^{-}(aq.)\rightarrow 2Ce^{3+}(aq.)+I_3^-(aq.)$

Oxidation half reaction: $Ce^{4+}(aq.)\rightarrow Ce^{3+}(aq.)+e^-$ ( × 2)

Reduction half reaction: $3I^_(aq.)+2e^-\rightarrow I_3^-(aq.)$

We are given:

$n=2\\E^o_{cell}=+1.08V\\F=96500$

Putting values in equation 1, we get:

$\Delta G^o=-2\times 96500\times (+1.80)=-347,400J=-347.4kJ$

Hence, the standard Gibbs free energy of the reaction is -347.4 kJ

For b:

The given chemical equation follows:

$6Fe^{3+}(aq.)+2Cr^{3+}+7H_2O(l)(aq.)\rightarrow 6Fe^{2+}(aq.)+Cr_2O_7^{2-}(aq.)+14H^+(aq.)$

Oxidation half reaction: $Fe^{3+}(aq.)\rightarrow Fe^{2+}(aq.)+e^-$ ( × 6)

Reduction half reaction: $2Cr^{2+}(aq.)+7H_2O(l)+6e^-\rightarrow Cr_2O_7^{2-}(aq.)+14H^+(aq.)$

We are given:

$n=6\\E^o_{cell}=-1.29V\\F=96500$

Putting values in equation 1, we get:

$\Delta G^o=-6\times 96500\times (-1.29)=746,910J=746.91kJ$

Hence, the standard Gibbs free energy of the reaction is 746.91 kJ

7 0

3 years ago

A compound with an empirical formula of C4H4O and a molar mass of 136 g/mol. What is the molecular formula of this compound?

fredd [130]

Answer:

C8H8O2

Explanation:

The molecular formula of a compound is simply a multiple of the empirical formula as shown below:

Molecular formula => [C4H4O]n

From the question given, we were told that molar mass of the compound is 136g/mol. This implies that:

[C4H4O]n = 136

Now, let us find the value of n in order to obtain the desired result. This is illustrated below:

[C4H4O]n = 136

[(12x4) + (4x1) + 16]n = 136

[48 + 4 + 16]n = 136

68n = 136

Divide both side by the coefficient of n i.e 68

n = 136/68

n = 2

Therefore the molecular formula is

=> [C4H4O]n

=> [C4H4O]2

=> C8H8O2

8 0

3 years ago

A shape with five sides is called a?

Elden [556K]

Answer:

A five-sided shape is called a pentagon.

Explanation:

Answered by NONE other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO!!!

Hope this helped!!!

8 0

3 years ago

Read 2 more answers

Testbank, Question 098 In the reaction between an alkyne and Na metal in liquid ammonia, the role of Na is as a(n) ___________.

KonstantinChe [14]

Answer:

d. reducing agent

Explanation:

Na acts as a reducing agent. A reducing agent is a substance whose function is to reduce or donate electrons to another, and by doing so it becomes oxidized. We can see the mechanism of the reaction in the image attached below.

4 0

3 years ago

If the salt created from the reaction of a strong acid and a weak base is added to a solution, what will happen to the solution

hoa [83]

Answer:

See Explanation

Explanation:

When a salt is dissolved in water, the solution could be acidic, basic or neutral depending on the nature of acid and base from which the salt was formed.

When a salt is formed from a strong acid and a weak base, the salt solution is acidic.

For instance, NH4Cl is a salt formed from NH3 which is a weak base and HCl which is a strong acid. The salt hydrolyses as follows;

NH4^+(aq) + H2O(l) ------> H3O^+(aq) + NH3(aq)

Hence an acidic solution is formed.

4 0

3 years ago