Answer:
3.41 g
Explanation:
<em>A chemist adds 260.0 mL of a 0.0832M potassium permanganate solution to a reaction flask. Calculate the mass in grams of potassium permanganate the chemist has added to the flask. Round your answer to 3 significant digits.</em>
Step 1: Given data
Volume of the solution (V): 260.0 mL (0.2600 L)
Concentration of the solution (C): 0.0832 M (0.0832 mol/L)
Step 2: Calculate the moles (n) of potassium permanganate added
We will use the following expression.
n = C × V
n = 0.0832 mol/L × 0.2600 L = 0.0216 mol
Step 3: Calculate the mass corresponding to 0.0216 moles of potassium permanganate
The molar mass of potassium permanganate is 158.03 g/mol.
0.0216 mol × 158.03 g/mol = 3.41 g
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The concentration of copper in the solution is
![5.1 \times 10^{18} \: M.](https://tex.z-dn.net/?f=5.1%20%5Ctimes%2010%5E%7B18%7D%20%20%5C%3A%20M.)
The volume of the solution = 1.00 L
![Moles \: of \:Cu(NO_{3}) _{2} = 2.50 \times 10 {}^{ - 4}](https://tex.z-dn.net/?f=Moles%20%5C%3A%20of%20%5C%3ACu%28NO_%7B3%7D%29%20_%7B2%7D%20%3D%202.50%20%5Ctimes%2010%20%7B%7D%5E%7B%20-%204%7D%20)
![Moles \: of \: Ethylenediamine = 1.20 \times 10.3](https://tex.z-dn.net/?f=Moles%20%5C%3A%20%20of%20%20%5C%3A%20Ethylenediamine%20%3D%201.20%20%5Ctimes%2010.3)
![k _{f} = 1.00 \times 10^{20}](https://tex.z-dn.net/?f=k%20_%7Bf%7D%20%3D%201.00%20%5Ctimes%2010%5E%7B20%7D%20)
Overall balanced equation of reaction is,
![Cu^{2 + }(aq) \: + 2en \: (aq)→ Cu(en) ^{2 + }_{2}(aq)](https://tex.z-dn.net/?f=Cu%5E%7B2%20%2B%20%7D%28aq%29%20%20%5C%3A%20%20%2B%202en%20%5C%3A%20%28aq%29%E2%86%92%20Cu%28en%29%20%5E%7B2%20%2B%20%7D_%7B2%7D%28aq%29)
![Moles \: of \:Cu(NO_{3}) _{2} =0.00025 \: mol](https://tex.z-dn.net/?f=Moles%20%5C%3A%20of%20%5C%3ACu%28NO_%7B3%7D%29%20_%7B2%7D%20%3D0.00025%20%5C%3A%20mol)
Mole ratio for,
![Moles \: of\:Cu(NO_{3}) _{2}: en](https://tex.z-dn.net/?f=Moles%20%5C%3A%20of%5C%3ACu%28NO_%7B3%7D%29%20_%7B2%7D%3A%20en)
![2: 1](https://tex.z-dn.net/?f=2%3A%201)
![Moles \: of \: en = 0.000250 \times 2](https://tex.z-dn.net/?f=Moles%20%5C%3A%20of%20%5C%3A%20en%20%3D%200.000250%20%5Ctimes%202)
![= 0.00050 \: moles](https://tex.z-dn.net/?f=%20%3D%200.00050%20%5C%3A%20moles)
Remained moles of en are= (0.00120-0.000500)
![= 0.000700 \: moles](https://tex.z-dn.net/?f=%20%3D%200.000700%20%5C%3A%20moles)
The concentration of copper in the solution is,
![k_{f} = \frac{Cu(en)^{2 + }_{2} }{Cu^{2+}en^{2} }](https://tex.z-dn.net/?f=k_%7Bf%7D%20%3D%20%20%5Cfrac%7BCu%28en%29%5E%7B2%20%2B%20%7D_%7B2%7D%20%20%7D%7BCu%5E%7B2%2B%7Den%5E%7B2%7D%20%20%7D)
![1.00 \times 10 ^{20} = \frac{0.000250}{(Cu )^{2 +} \times (0.000700)^{2 + } }](https://tex.z-dn.net/?f=1.00%20%5Ctimes%2010%20%5E%7B20%7D%20%3D%20%20%5Cfrac%7B0.000250%7D%7B%28Cu%20%29%5E%7B2%20%2B%7D%20%20%5Ctimes%20%280.000700%29%5E%7B2%20%2B%20%7D%20%7D)
![= 5.1 \times 10^{18} \: M.](https://tex.z-dn.net/?f=%20%3D%20%205.1%20%5Ctimes%2010%5E%7B18%7D%20%20%5C%3A%20M.)
Therefore, the concentration of copper in the solution is
![5.1 \times 10^{18} \: M.](https://tex.z-dn.net/?f=5.1%20%5Ctimes%2010%5E%7B18%7D%20%20%5C%3A%20M.)
To know more about molarity, refer to the below link:
brainly.com/question/8732513
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Answer:
Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N 2) and about 21% oxygen (O 2).
In short, Nitrogen
Answer: If more than one variable is changed in an experiment, scientist cannot attribute the changes or differences in the results to one cause. By looking at and changing one variable at a time, the results can be directly attributed to the independent variable.