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marta [7]
4 years ago
11

The chemical reaction 2Cu + O2 → 2CuO + 315 kJ is an _____ reaction. Endothermic, combustion Exothermic, combustion Endothermic,

single replacement Exothermic, single replacement
Chemistry
2 answers:
Kobotan [32]4 years ago
8 0

Answer: Exothermic

Explanation: Combustion reaction is a chemical reaction in which hydrocarbon burns in the presence of oxygen to form carbon dioxide, water and energy.

Exothermic reactions are those in which energy is released and endothermic reactions are those in which energy is absorbed.

A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.

2Cu+O_2\rightarrow 2CuO+315kJ

As in the given reaction, the energy is released thus reaction s exothermic.

makvit [3.9K]4 years ago
4 0

the awnser is exothermic (combustion)


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Given the following UNBALANCED reaction: NH3 (g) <--> N2 (g) + H2 (g) If 1
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C. 1.35

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                                                     2NH3 (g) <-->          N2 (g) +             3H2 (g)

Initial concentration                2.2 mol/0.95L       1.1 mol/0.95L           0

change in concentration        2x                             x                           3x

                                                 -0.84 M                  +0.42M                +1.26M

Equilibrium                       1.4 mol/0.95L=1.47M        1.58 M                   1.26 M

concentration

Change in concentration(NH3) = (2.2-1.4)mol/0.95 L = 0.84M

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8 0
3 years ago
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The original mass of krypton 81 that is present in the ice is 6.70 grams.

<h3>How do we calculate original mass?</h3>

Original mass of any substance will be calculated as below for the decomposition reaction is:

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N = remaining mass of krypton-81 = 1.675g

N₀ = original mass of krypton-81 = ?

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n = 458,000/229,000 = 2

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To know more about half life time, visit the below link:
brainly.com/question/2320811

8 0
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