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ioda
3 years ago
7

How many kilowatt-hours of electricity are used to produce 4.50 kg of magnesium in the electrolysis of molten mgcl2 with an appl

ied emf of 5.00 v?
Chemistry
1 answer:
ratelena [41]3 years ago
3 0
First, we need to determine the half reaction of magnesium. It would be expressed as:

Mg2+ + 2e- = Mg

Given the mass of magnesium metal that is produced, we calculate the total charge of the electrolysis by the relations we can get from the half reaction. We do as follows:

4.50 kg Mg ( 1000 g / 1 kg ) ( 1 mol / 24.305 g ) ( 2 mol e- / 1 mol Mg ) ( 96500 C / 1 mol e- ) = 35733388.2 C

We are given the applied EMF in units of V. This value is equal to J/C. So, 5 V is equal to 5 J/C.

35733388.2 C (5 J/C) = 178666941 J
178666941 J ( 1 kW-h / 3.6x10^6 J ) = 49.63 kW-h
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Sulfuric acid is formed when sulfur dioxide reacts with oxygen and water. Write a balanced chemical equation for the reaction. (
Nesterboy [21]

Balanced chemical equation for the reaction is:

2SO_{2} (g) + O_{2} (g)+ 2H_{2}O (l) ⇒H_{2} S_{} O_{4}

Moles of H_{2} S_{} O_{4} formed is 5.75 moles.

Moles of oxygen used is 5.75 moles in the reaction.

Explanation:

Data given:

moles of SO_{2} = 11.5 moles

moles of H_{2} S_{} O_{4} = ?

Moles of O_{2} needed =?

balanced equation with states of matter =?

Balanced chemical reaction under STP condition is given as:

2SO_{2}(g) + O_{2} (g) + 2H_{2}O (l) ⇒H_{2} S_{} O_{4}

From the balanced reaction 2 moles of sulphur dioxide reacted to form 1 mole of sulphuric acid:

so, from 11.5 moles of SO_{2}, x moles of H_{2} S_{} O_{4} is formed

\frac{1}{2}  =\frac{x}{11.5}

2x = 11.5

x = 5.75 moles of sulphuric acid formed.

From the balanced reaction 1 mole of oxygen reacted to form 1  mole of sulphuric acid.

when 11.5 moles of Sulphur dioxide reacted then oxygen in the reaction is 5.75 moles.

7 0
3 years ago
When an electron moves from a lower energy level to a higher energy level, the atom:
Ede4ka [16]

Answer:

A. absorbs light

Explanation:

For an electron to move from a lower energy level to a higher energy level, energy needs to be added to the atom.

In most cases this required energy will be light: The electron of the atom will absorb the energy of the light and move to a higher energy level.

When said electron comes back to the lower energy level, the atom will conversely give off light.

5 0
3 years ago
Does anybody know the answer to these two questions ?
Serjik [45]
the first is hydroxide. I believe d is the second one but I'm not 100% positive so you may want to get a second opinion
4 0
3 years ago
an atom of chlorine has an amount number of 17 and a mass number of 37. how many protons neutrons, and electrons are in the atom
Soloha48 [4]

Answer: There are 20 protons neutrons in the atom

6 0
2 years ago
2. A sample of oxygen gas is placed in a rigid 1.5L glass container at STP. If the gas is
sladkih [1.3K]

The new pressure : P₂ = 1038.39 mmHg

<h3>Further explanation</h3>

Given

1.5 L container at STP

Heated to 100 °C

Required

The new pressure

Solution

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure).

So P₁ =  1 atm = 760 mmHg

T₁ = 273 K

T₂ = 100 °C+273 = 373 K

Gay Lussac's Law  

When the volume is not changed, the gas pressure is proportional to its absolute temperature  

\tt \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}

Input the value :

P₂=(P₁.T₂)/T₁

P₂=(760 x 373)/273

P₂ = 1038.39 mmHg

7 0
3 years ago
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