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2 years ago

Will give brainliest if you answer quickly and correctly :)

Chemistry

2 answers:

joja [24]2 years ago

5 0

Answer:

C. I (iodine)

Explanation:

it would be Iodine because it has 5 energy levels of electrons and has a total of 74 neutrons inside its nucleus!

Hope this helps, have a good day!

AnnZ [28]2 years ago

3 0

I think it’s I
Iodine has 53 protons and 74 neutrons

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The vapor pressure of benzene at 298 K is 94.4 mm of Hg. The standard molar Gibbs free energy of formation of liquid benzene at

horsena [70]

Answer:

ΔfG°(C₆H₆(g)) = 129.7kJ/mol

Explanation:

Bringing out the parameters mentioned in the question;

Vapor pressure = 94.4 mm of Hg

The vaporization reaction is given as;

C₆H₆(l) ⇄ C₆H₆(g)

Equilibrium in terms of activities is given by:

K = a(C₆H₆(g)) / a(C₆H₆(l))

Activity of pure substances is one:

a(C₆H₆(l)) = 1

Assuming ideal gas phase activity equals partial pressure divided by total pressure. At standard conditions

K = p(C₆H₆(g)) / p°

Where p° = 1atm = 760mmHg standard pressure

We now have;

K = 94mmHg / 760mmHg = 0.12421

Gibbs free energy is given as;

ΔG = - R·T·ln(K)

where R = gas constant = 8.314472J/molK

So ΔG° of vaporization of benzene is:

ΔvG° = - 8.314472 · 298.15 · ln(0.12421)

ΔvG° = 5171J/mol = 5.2kJ/mol

Gibbs free energy change of reaction = Gibbs free energy of formation of products - Gibbs free energy of formation of reactants:

ΔvG° = ΔfG°(C₆H₆(g)) - ΔfG°(C₆H₆(l))

Hence:

ΔfG°(C₆H₆(g)) = ΔvG°+ ΔfG°(C₆H₆(l))

ΔfG°(C₆H₆(g)) = 5.2kJ/mol + 124.5kJ/mol

ΔfG°(C₆H₆(g)) = 129.7kJ/mol

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3 years ago

An ice cube melts to become water in a cup. how will the ice cube and the water be the same?

kenny6666 [7]

They will stay the same through the laws of conservation of mass even when they have changed state so they will have the reactant of Ice will be the same amount as the product of water

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3 years ago

Elements within a period have ___.

Vlada [557]

Ans: Have the same number of electron shells

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3 years ago

A solution contains 0.115 mol h2o and an unknown number of moles of nacl. the vapor pressure of the solution at 30°c is 25.7 tor

Valentin [98]

According to Raoult's low:
We will use this formula: Vp(Solution) = mole fraction of solvent * Vp(solvent)
∴ mole fraction of solvent = Vp(Solu) / Vp (Solv)
when we have Vp(solu) = 25.7 torr & Vp(solv) = 31.8 torr
So by substitution:
∴ mole fraction of solvent = 25.7 / 31.8 =0.808
when we assume the moles of solute NaCl = X
and according to the mole fraction of solvent formula:
mole fraction of solvent = moles of solvent / (moles of solvent + moles of solute)
by substitute:
∴ 0.808 = 0.115 / (0.115 + X)
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2 years ago

What stress will shift the following equilibrium system to the left?

Alona [7]

Answer: Increasing temperature

Explanation:

The Principle of Le Chatelier states that if a system in equilibrium is subjected to a change of conditions, it will move to a new position in order to counteract the effect that disturbed it and recover the state of equilibrium.

The variation of one or several of the following factors can alter the equilibrium condition in a chemical reaction:

Temperature
The pressure
The volume
The concentration of reactants or products

In the case of the reaction in the question, the change that moves the balance to the left will be the one that moves it towards the reagents, that is, that favors the production of reagents instead of products.

Decreasing the concentration of SO3 and increasing the concentration of SO2 will favor the production of SO3, which is the product of the reaction.
Decreasing the volume increases the pressure of the system and the balance will move to where there is less number of moles. In the case of the reaction in question, we have 3 moles of molecules in the reactants (1 mole of O2 + 2 moles of SO2) while in the products there are 2 moles of SO3 only, therefore, decreasing the volume will displace the balance to the right, which corresponds to the sense in which there is less number of moles.

The reaction of the question is an exothermic since ΔH <0, therefore in the reaction heat is produced and it can be written in the following way,

2SO2(g) + O2(g) ⇌ 2SO3(g) + heat

So, if we increase the temperature we will be adding heat to the system, so the balance would move to the left to compensate for the excess heat in the system.

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3 years ago