Answer:
Mass of hydrogen gas evolved is 0.0749 grams.
Explanation:
Total pressure of the gases = p = 758 mmHg
Vapor pressure of water = 23.78 mmHg
Pressure of hydrogen gas ,P = p - 23.78 mmHg = 758 mmHg - 23.78 mmHg
P = 734.22 mmHg = 
Temperature of of hydrogen gas ,T= 25°C =298.15 K
Volume of hydrogen gas = V = 0.949 L
Moles of hydrogen gas =n
PV = nRT (Ideal gas equation )
n = 0.03745 mol
Moles of hydrogen gas = 0.03745 mol
Mass of 0.03745 moles of hydrogen gas = 0.03745 mol × 2 g/mol = 0.0749 g
Mass of hydrogen gas evolved is 0.0749 grams.
An igneous rock is defined by how the rock is formed; igneous rocks are formed by the solidification of molten rock materials. Examples of igneous rocks include Diorite, Gabbro, Granite, Pegmatite.
Answer:
Explanation:
The first reaction is oxidation of Mn to Mn²⁺ with HNO₃:
(4H⁺ + NO₃⁻ + 3e⁻ → NO + 2H₂O) x2
(Mn → Mn²⁺ + 2e⁻) x3
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(1) 3Mn + 8H⁺ + 2NO₃⁻ → 3Mn²⁺ + 2NO + 4H₂O
The oxidation to MnO₄⁻ with IO₄⁻ is:
(2e⁻ + 2H⁺ + IO₄⁻ → IO₃⁻ + H₂O) x5
(Mn²⁺ + 4 H₂O → MnO₄⁻ + 8H⁺ + 5e⁻) x2
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(2) 2Mn²⁺ + 5IO₄⁻ + 3H₂O → 2MnO₄⁻ + 5IO₃⁻ + 6H⁺
Answer:
It isn't.
Explanation:
It is a counting unit for "things" — atoms, molecules, ions, etc. — and these things all have different masses.
For example, a chemist may know that one atom of Cu reacts with one atom of S to form one molecule of CuS.
Cu + S ⟶ CuS
She knows that 1 mol of Cu (6.022 × 10²³ atoms of Cu) has a mass of 63.55 g and 1 mol of S (6.022 × 10²³ atoms of S) has a mass of 32.06 g.
By measuring out 63.55 g of Cu and 32.06 g of S, she knows that there are just enough atoms of each element to react with each other.
Thus, the mole has enabled her to count atoms.
