Question

Вычеслите массу и колличество вещества гидроксида калия, который можно получить при полном взаимодействии с водой 78 г калия.

Answer 1

   78 г                    m=? n=?

  2K    +    2H2O   =  2KOH   +  H2

n= 2 моль               n=2 моль

М=39 г/моль          М= 56 г/моль

m=78 г                   m= 112 г

78 г К    -     Х моль КОН

78 г К   -     2 моль КОН

n(KOH) = 78 * 2 / 78 = 2 моль

78 г К    -    х г КОН

78 г К   -    112 г КОН

m(KOH) = 78 * 112/78 = 112 г

Answer 2

Calculation of the Mass and Amount of Potassium Hydroxide

To calculate the mass and amount of potassium hydroxide (KOH) that can be obtained from the complete reaction with 78 g of potassium (K), we need to consider the balanced chemical equation for the reaction between potassium and water.

The balanced chemical equation for the reaction is as follows: 2K + 2H2O -> 2KOH + H2

From the balanced equation, we can see that 2 moles of potassium react with 2 moles of water to produce 2 moles of potassium hydroxide and 1 mole of hydrogen gas.

To calculate the mass and amount of potassium hydroxide, we need to determine the molar mass of potassium hydroxide (KOH). The molar mass of KOH is calculated by adding the atomic masses of potassium (K), oxygen (O), and hydrogen (H).

The atomic masses are as follows: - Potassium (K): 39.10 g/mol - Oxygen (O): 16.00 g/mol - Hydrogen (H): 1.01 g/mol

Therefore, the molar mass of KOH is: 39.10 g/mol (K) + 16.00 g/mol (O) + 1.01 g/mol (H) = 56.11 g/mol

Now, let's calculate the mass and amount of potassium hydroxide.

Calculation:

1. Calculate the moles of potassium (K) using the given mass of potassium: - Mass of potassium (K) = 78 g - Molar mass of potassium (K) = 39.10 g/mol - Moles of potassium (K) = Mass of potassium (K) / Molar mass of potassium (K)

2. Since the balanced equation shows that 2 moles of potassium react to produce 2 moles of potassium hydroxide (KOH), the moles of potassium hydroxide (KOH) will be the same as the moles of potassium (K).

3. Calculate the mass of potassium hydroxide (KOH) using the moles of potassium hydroxide (KOH) and the molar mass of potassium hydroxide (KOH): - Moles of potassium hydroxide (KOH) = Moles of potassium (K) - Molar mass of potassium hydroxide (KOH) = 56.11 g/mol - Mass of potassium hydroxide (KOH) = Moles of potassium hydroxide (KOH) * Molar mass of potassium hydroxide (KOH)

Answer:

The mass of potassium hydroxide (KOH) that can be obtained from the complete reaction with 78 g of potassium (K) is 78 g.

The amount of potassium hydroxide (KOH) that can be obtained from the complete reaction with 78 g of potassium (K) is 1.39 moles.

Please note that the above calculations are based on the assumption of a complete reaction and ideal conditions. In practice, the actual yield may be lower due to various factors such as side reactions and incomplete conversion.