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sweet [91]
3 years ago
5

Compare the type of change that occurs when an iron bar rusts and when a substance freezes.

Chemistry
1 answer:
Ivanshal [37]3 years ago
5 0

Explanation:

when an iron bar rust is an example of a chemical change in which a new substance is formed and the change is not easily reversible.for iron to rust moisture and air must be present.while when a substance freezes,it can be easily reversed through melting and no new substance is formed.this change is termed a physical change.

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If a 67.3G rock is dissolved in 2.00L of acid, what is the molar concentration of gold in the acid solution
brilliants [131]

Answer:

[Au] = 0.171 M

Explanation:

For this question, we assume the rock is 100 % gold.

First of all, we determine the moles of gold

67.3 g . 1mol/ 196.97g = 0.342 moles

Molar concentration is defined as the moles of solute, contained in 1L of solution.

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Molar concentration, also called molarity of solution is the most typical unit of concentration.

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Answer:

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<u>Using:</u>

<u>AH° (kcal/mol) </u>

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For the reaction:

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The balanced reaction is:

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ΔH CCl₄(g): -33,3 kcal/mol

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The ΔHr is:

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<em>ΔHr = -103,4 kcal/mol</em>

<em></em>

I hope it helps!

3 0
3 years ago
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