Question

Вычислите массу перманганата калия KMnO4 при полном разложении которого получили манганат калия K2MnO4 диоксид марганца MnO2 и 5,6 литров кислорода

Answer 1

2KMnO4=MnO2+K2MnO4+O2  1)n(O2)=5.5/22.4=0.25 моль 2)n(KMnO4)=n(O2)*2=0.5 моль 3)m(KMnO4)=0.5*158=79 г

Answer 2

Calculation of the Mass of Potassium Permanganate (KMnO4)

To calculate the mass of potassium permanganate (KMnO4) when it undergoes complete decomposition to form potassium manganate (K2MnO4), manganese dioxide (MnO2), and 5.6 liters of oxygen, we need to consider the balanced chemical equation for the reaction.

The balanced chemical equation for the decomposition of potassium permanganate is as follows:

2 KMnO4 -> K2MnO4 + MnO2 + O2

From the balanced equation, we can see that 2 moles of KMnO4 decompose to form 1 mole of K2MnO4, 1 mole of MnO2, and 1 mole of O2.

To calculate the mass of KMnO4, we need to know the molar masses of KMnO4, K2MnO4, MnO2, and O2.

The molar masses are as follows: - KMnO4: 39.10 g/mol (potassium: 39.10 g/mol, manganese: 54.94 g/mol, oxygen: 16.00 g/mol) - K2MnO4: 198.20 g/mol (potassium: 39.10 g/mol, manganese: 54.94 g/mol, oxygen: 16.00 g/mol) - MnO2: 86.94 g/mol (manganese: 54.94 g/mol, oxygen: 16.00 g/mol) - O2: 32.00 g/mol (oxygen: 16.00 g/mol)

Now, let's calculate the mass of KMnO4:

1. Calculate the number of moles of O2: - We are given that 5.6 liters of oxygen are produced. - To convert liters to moles, we need to use the ideal gas law. - At standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 liters. - Therefore, the number of moles of O2 can be calculated as follows: Moles of O2 = (5.6 liters) / (22.4 liters/mol) = 0.25 mol

2. Use the stoichiometry of the balanced equation to determine the number of moles of KMnO4: - From the balanced equation, we know that 2 moles of KMnO4 decompose to form 1 mole of O2. - Therefore, the number of moles of KMnO4 can be calculated as follows: Moles of KMnO4 = 2 * Moles of O2 = 2 * 0.25 mol = 0.5 mol

3. Calculate the mass of KMnO4: - The mass of KMnO4 can be calculated by multiplying the number of moles of KMnO4 by its molar mass: Mass of KMnO4 = Moles of KMnO4 * Molar mass of KMnO4 = 0.5 mol * 39.10 g/mol = 19.55 g

Therefore, the mass of potassium permanganate (KMnO4) obtained from the complete decomposition, which produces potassium manganate (K2MnO4), manganese dioxide (MnO2), and 5.6 liters of oxygen, is approximately 19.55 grams.

Please note that the given search snippets did not provide direct information for this specific calculation. However, the calculation is based on the balanced chemical equation and the molar masses of the compounds involved.