Answer:
There are 0,011 moles of hydrogen gas.
Explanation:
We use the ideal gas formula, with the constant R = 0.082 l atm / K mol. The STP conditions are : 1 atm pressure and 273 K temperature. Solve for the formula, n (number of moles):
PV=nRT ---> n= (PV)/(RT)
n= (1 atm x 0,25 L)/ (0,082 l atm/ K mol x 273 K)
<em>n= 0,011 mol</em>
Data:
![M_{concentrated} = 2.5\:mol](https://tex.z-dn.net/?f=M_%7Bconcentrated%7D%20%3D%202.5%5C%3Amol)
![V_{concentrated} = ?](https://tex.z-dn.net/?f=V_%7Bconcentrated%7D%20%3D%20%3F)
![M_{dilute} = 0.50\:mol](https://tex.z-dn.net/?f=M_%7Bdilute%7D%20%3D%200.50%5C%3Amol)
![V_{dilute} = 100\:mL\to0.100\:L](https://tex.z-dn.net/?f=V_%7Bdilute%7D%20%3D%20100%5C%3AmL%5Cto0.100%5C%3AL)
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Formula: Dilution Calculations
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![M_{concentrated} * V_{concentrated} = M_{dilute} * V_{dilute}](https://tex.z-dn.net/?f=M_%7Bconcentrated%7D%20%2A%20V_%7Bconcentrated%7D%20%3D%20M_%7Bdilute%7D%20%2A%20V_%7Bdilute%7D%20)
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Solving:
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![M_{concentrated} * V_{concentrated} = M_{dilute} * V_{dilute}](https://tex.z-dn.net/?f=M_%7Bconcentrated%7D%20%2A%20V_%7Bconcentrated%7D%20%3D%20M_%7Bdilute%7D%20%2A%20V_%7Bdilute%7D%20)
![2.5 * V_{concentrated} = 0.50 * 0.100](https://tex.z-dn.net/?f=2.5%20%2A%20V_%7Bconcentrated%7D%20%3D%200.50%20%2A%200.100%20)
![2.5V_{concentrated} = 0.05](https://tex.z-dn.net/?f=2.5V_%7Bconcentrated%7D%20%3D%200.05)
![V_{concentrated} = \frac{0.05}{2.5}](https://tex.z-dn.net/?f=V_%7Bconcentrated%7D%20%3D%20%20%5Cfrac%7B0.05%7D%7B2.5%7D%20)
![\boxed{\boxed{V_{concentrated} = 0.02\:L\:or\:20\:mL}} \end{array}}\qquad\quad\checkmark](https://tex.z-dn.net/?f=%5Cboxed%7B%5Cboxed%7BV_%7Bconcentrated%7D%20%3D%200.02%5C%3AL%5C%3Aor%5C%3A20%5C%3AmL%7D%7D%20%5Cend%7Barray%7D%7D%5Cqquad%5Cquad%5Ccheckmark)
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When the same species undergoes both oxidation and reduction in a single redox reaction, this is referred to as a disproportionation. Therefore, divide it into two equal reactions.
NO2→NO^−3
NO2→NO
and do the usual changes
First, balance the two half reactions:
3. NO2 +H2O →NO^−3 + 2 H^+ + e−
4. NO2 +2 H^+ + 2e− → NO + H2O
Now multiply one or both half-reactions to ensure that each has the same number of electrons. Here, Eqn (3) x 2 results in each half-reaction having two electrons:
5. 2 NO2 + 2 H2O → 2 NO^−3 + 4H^+ + 2e−
Now add Eqn 4 and 5 (the electrons now cancel each other):
3NO2 + 2H^+ + 2H2O → NO + 2 NO−3 + H2O + 4H+
and cancel terms that’s common to both sides:
3NO2 + H2O → NO + 2NO^−3 + 2H+
This is the net ionic equation describing the oxidation of NO2 to NO3 in basic solution.
Learn more about balancing equation here:
brainly.com/question/26227625
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