Question 14 of 25

When silver nitrate is added to the Fe/SCN equilibrium, why is the colorless intense and a precipitate forms?

Reptile [31]

Answer:

Here's what I get

Explanation:

You have an equilibrium reaction between Fe³⁺/ SCN⁻ and FeSCN²⁺.

$\underbrace{\hbox{Fe$^{3+}$}}_{\text{pale yellow-green}} +\underbrace{\hbox{SCN$^{-}$}}_{\text{colourless}} \, \rightleftharpoons \, \underbrace{\hbox{Fe(SCN)$^{2+}$}}_{\text{deep blood red}} \\$

When you add AgNO₃, the Ag⁺ reacts with the SCN⁻. It forms a colourless precipitate of Ag(SCN).

Ag⁺(aq) + SCN⁻(aq) ⟶ AcSCN(s)

According to Le Châtelier's Principle, when we apply a stress to a system at equilibrium, the system will respond in a way that tends to relieve the stress.

If you add Ag⁺ to the equilibrium solution, it removes the SCN⁻ [as an Ag(SCN) precipitate].

The system responds by trying to replace the missing SCN⁻:

The Fe(SCN)²⁺ dissociates to form SCN⁻, so the position of equilibrium shifts to the left,

You now have more Fe³⁺ and SCN⁻ and less of the highly coloured Fe(SCN)²⁺ at the new equilibrium.

The deep red colour becomes less intense.

3 0

3 years ago

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper; the aluminum and the copper are in

Illusion [34]

Answer:

Copper is the object that experiences the greater temperature change.

Explanation:

Thermally isolated system means that the system does not exchange thermal energy with the surroundings.

Hence, any thermal exchange, in virtue of the temperature difference of the aluminum and copper pieces, is between them.

In consequence, the law of conservation of energy states that the heat lost by the hot substance will be gained by the cold matter.

In equations, that is:

Heat lost by aluminum = heat gained by copper.

Now, the gain or loss or heat of a substance, Q, is related with the mass (m), the specific heat (Cs), and the cahnge of temperature (ΔT), per the equation:

Q = m × Cs × ΔT

∴ Q lost by aluminum = Q gained copper ⇒

[m × Cs × ΔT ] aluminum = [m × Cs × ΔT ] copper.

Under the reasoning assumption that the masses of aluminum and copper are equal, the equations is simplified to:

[Cs × ΔT ] aluminum = [Cs × ΔT ] copper.

Cs aluminum / Cs copper = ΔT copper / ΔT aluminum

Cs aluminum > 2 × Cs copper ⇒ Cs

Cs aluminum / Cs copper > 2 ΔT copper / ΔT aluminum

ΔT copper / ΔT aluminum > 2

ΔT copper > 2 × ΔT aluminum

In words, since it is stated that the specific heat of aluminum is more than double that of copper, in order to keep the equality, ΔT of copper shall be more than double ΔT of aluminum.

Hence, the conclusion is that the object that experiences the greater temperature change is copper (the one with the lower specific heat), under the assumption that both objects have the same amount of matter (mass).

6 0

3 years ago

The electronegativity of nitrogen (N) is 3.0, while the electronegativity of hydrogen (H) is 2.1. Knowing this, consider how the

Ede4ka [16]

Answer:

NH3 is polar due to the bonds between nitrogen and hydrogen which have different electronegativity and due also to its asymmetrical shape.

Explanation:

NH3 is polar as there are 3 dipoles in the ammonia molecule that do not balance each other out.

Considering the N-H bond which is polar because N with an electronegativy of 3.0, is more electronegative than H, with an electronegativity of 2.1. The is overall asymmetrical shape of NH3

means that the dipoles remains unbalanced and do cancel out each other making the NH3 polar.

4 0

3 years ago

Complete the table by classifying each property as either a physical or chemical property

Advocard [28]

Where is the table? I dont know what to classify

8 0

3 years ago

The Aurora Borealis or northern light occur when solar flares react with the atmosphere near the north poles. The Aurora give of

scoray [572]

Answer: C) plasma

Natural phenomena characterized by colored lights in the sky, is caused by the interaction of charged particles of energy from the solar wind with the magnetic layer of the earth so we have turbulence and multicolored plasma clouds known as auroras arise.

4 0

3 years ago

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