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3 years ago

Consider the following intermediate chemical equations.

Chemistry

1 answer:

vfiekz [6]3 years ago

8 0

Answer:

-250.3kJ

Explanation:

Based in the reactions and using -<em>Hess's law-</em>:

(1) P₄(s) + 6 Cl₂(g) → 4PCl₃(g) ΔH₁ = -4439kJ

(2) 4PCl₅(g) → P₄(s) + 10Cl₂ ΔH₂ = 3438kJ

The sum of (1) + (2) is:

4PCl₅(g) → 4PCl₃(g) + 4 Cl₂ ΔH = -4439kJ + 3438kJ = -1001kJ

Dividing this reaction in 4:

PCl₅(g) → PCl₃(g) + Cl₂ ΔH = -1001kJ / 4 = <em>-250.3kJ</em>

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PREDICT Do you think warming a cannonball in a fire has any effect

Zanzabum

I think yes because the heat from the fire will transferred to the cannon ball and it will cause something with its energy to change effect.

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2 years ago

In the Hall-Heroult process, a large electric current is passed through a solution of aluminum oxide Al2O3 dissolved in molten c

Darya [45]

Answer:

0.382g

Explanation:

Step 1: Write the reduction half-reaction

Al³⁺(aq) + 3 e⁻ ⇒ Al(s)

Step 2: Calculate the mass of Al produced when a current of 100. A passes through the cell for 41.0 s

We will use the following relationships.

1 A = 1 C/s

1 mole of electrons has a charge of 96486 C (Faraday's constant)

1 mole of Al is produced when 3 moles of electrons pass through the cell.

The molar mass of Al is 26.98 g/mol.

The mass of Al produced is:

$41.0s \times \frac{100C}{s} \times \frac{1mole^{-} }{96486C} \times \frac{1molAl}{3mole^{-} } \times \frac{26.98gAl}{1molAl} = 0.382gAl$

7 0

3 years ago

Can someone check that I did this correctly? What does it mean by “networks” and “formula units”?

ale4655 [162]

Idk i just need to ask a question

6 0

3 years ago

For the following questions, use a periodic table and your atomic calculations to find the unknown information about each isotop

mafiozo [28]

Answer:

Option B is correct.

Explanation:

We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,

Number of neutrons + number of proton

2 + 2 = 4

Thus, option B is correct.

7 0

3 years ago

Both 1,2−dihydronaphthalene and 1,4−dihydronaphthalene may be selectively hydrogenated to 1,2,3,4−tetrahydronaphthalene. One of

pochemuha

Answer:

1,4-dihydro = 113 kJ·mol⁻¹

1,2-dihydro = 101 kJ·mol⁻¹

Explanation:

In 1,4-dihydronaphthalene, the 2,3-double bond is isolated from the benzene ring.

In 1,2-dihydronaphthalene, the 3,4-double bond is conjugated with the benzene ring.

Thus, 1,2-dihydronaphthalene is partially stabilized by resonance interactions between the ring and the double bond (think, styrene).

1,2-Dihydronaphthalene is at a lower energy level because of this stabilization.

The heat of hydrogenation of 1,2-dihydronaphthalene is therefore less than that of the 1,4-isomer when each is hydrogenated to the common product, 1,2,3,4-tetrahydronaphthalene.

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2 years ago