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3 years ago

Metals are extracted from their ores.

1 answer:

7 0

1. Copper is very useful, so people want as much as possible.
2. We are running out, so we are extracting all the copper that we can to keep up with our needs.

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A gas has a volume of 29.3 L at 28.8 atm. What will its volume be if the pressure is changed to 16.5 atm?

Irina18 [472]

Answer:

P₁V₁=P₂V₂

29.3 * 28.8 = 16.5* V₂

V₂ = 51.14 L

6 0

3 years ago

The standard free-energy changes for the reactions below are given.Phosphocreatine → creatine + Pi ∆ G'° = –43.0 kJ/molATP → ADP

Anton [14]

Answer:

Gibbs free-energy of the reaction = (–12.5 kJ/mol)

Explanation:

The Gibbs free-energy of a reaction predicts the spontaneity or feasibility of a given chemical reaction.

Given the standard Gibbs free energy changes:

Phosphocreatine → creatine + Pi, ∆G° = –43.0 kJ/mol ...(1)

ATP → ADP + Pi , ∆G° = –30.5 kJ/mol ....(2)

Now to calculate the Gibbs free-energy of the given chemical reaction: Phosphocreatine + ADP → creatine + ATP; the equation (2) is reversed to give:

ADP + Pi → ATP, ∆G° = + 30.5 kJ/mol ...(3)

Now the equation (3) and (1) are added, to give:

Phosphocreatine + ADP + Pi→ creatine + ATP + Pi

⇒ Phosphocreatine + ADP → creatine + ATP

Therefore, to calculate the Gibbs free-energy of the reaction, the standard Gibbs free energy changes of the equations (1) and (3) are added similarly:

Gibbs free-energy of the reaction: ∆G° = (–43.0 kJ/mol) + ( + 30.5 kJ/mol) = (–12.5 kJ/mol)

Therefore, the Gibbs free-energy of the reaction = (–12.5 kJ/mol)

7 0

3 years ago

For the reaction 4 Fe + 3 O2 -> Fe2 O3, explain how you would calculate the moles of iron needed to make 10 moles of Fe2O3

Hatshy [7]

Answer:

20 moles

Explanation:

4 Fe + 3O₂ → Fe₂O₃

The chemical equation provided is not yet balanced so let's start by balancing it.

4 Fe + 3O₂ → 2 Fe₂O₃

The equation is now balanced with 4 Fe atoms and 6 O atoms on both sides of the equation. It is important to ensure that the chemical equation is balanced, as only then will it tell you the relationship of the reactants and products in terms of mole.

Looking at the coefficients of Fe and Fe₂O₃, 4 moles of Fe is needed to make 2 moles of Fe₂O₃.

This can be simplified into the mole ratio below.

Fe: Fe₂O₃= 2: 1

This means that for every mole of Fe₂O₃, twice the amount of Fe (in moles) is needed.

Thus for 10 moles of Fe₂O₃,

amount of Fe needed

= 10 ×2

= 20 moles

3 0

3 years ago

.....k+.....HgCl2 gives u...... Hg+ KCl

worty [1.4K]

Answer:

2K + HgCl2 —> Hg + 2KCl

Explanation:

K + HgCl2 —> Hg + KCl

The above equation is not balanced

To balance the equation, do the following.

First, put 2 in front of KCl, the equation becomes,

K + HgCl2 —> Hg + 2KCl

Now we see that Cl is balanced but K is not. To balance K, put 2 in front of K as shown below:

2K + HgCl2 —> Hg + 2KCl

Now we can that the equation is balanced

5 0

3 years ago

To save time, you can approximate the initial mass of the solid to the nearest ±1 g. For example, if you are asked to add 14.3 g

tensa zangetsu [6.8K]

Answer: Set with equal densities are:

15.2 g copper and 50.0 g copper ; 11.2 g gold and 14.9 g gold

Explanation:

Density is defined as mass of the substance present in unit volume of the substance.

$Density=\frac{Mass}{Volume}$

It is an intensive property which means that two different masses of same substance will have same value of density under same conditions.

So, from the given samples with equal density are:

15.2 g copper and 50.0 g copper will have the same value density.

11.2 g gold and 14.9 g gold will have the same value density.

6 0

3 years ago

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