First compute the number of grams of manganese metal required to make 21.7 grams of H2.
21.7 g H2 x (1 mole H2/ 2 g H2) x (1 mole Mn/1 mol H2) x (55 grams Mn/1 mol Mn) = 596.75 grams
Now density = mass/volume
7.43 = 596.75/volume
volume = 596.75/7.43 = 80.31 mL
80.31 mL is the amount of manganese needed.
Thermal Energy, Electrical Energy, Light, Sound, Nuclear Energy, and Chemical Energy
The balanced chemical equation that illustrates this reaction is:
<span>C2H4 + 3O2 --> 2CO2 + 2H2O
</span>
From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
Therefore:
molar mass of C2H4 = 12(2) + 4(1) = 24 + 4 = 28 grams
number of moles = mass / molar mass
number of moles of C2H4 = 54.7 / 28 = 1.95 moles
From the balanced equation above:
3 moles of oxygen are required to react with one mole of C2H4, therefore, to know the number of moles required to react with 1.95 moles of C2H4, all you have to do is cross multiplication as follows:
number of oxygen moles = (1.95*3) / 1 = 5.85 moles
Answer:
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The order of the solutions from lowest to highest concentration : A, B, C
<h3>Further explanation</h3>
Given
the following solutions
Required
order of increasing concentration
Solution
Molarity shows the number of moles of solute in every 1 liter of solution.

Solution A : 0.5 moles : 2 L solution = 0.25 M
Solution B : 1 moles : 3 L solution = 0.33 M
Solution C : 1.5 moles : 4 L solution = 0.375 M