Question

7,8 г калия обработали 200 г воды. В образовавшийся раствор пропустили 2,24 л (н.у.) углекислого газа. Определите массу соли в образовавшемся растворе. Ответ: 13,8 г.

Answer 1

Решение в приложении).................................................................

Answer 2

Calculation of the Mass of Salt in the Solution

To calculate the mass of salt in the solution, we need to determine the amount of potassium hydroxide (KOH) that reacted with the carbon dioxide (CO2) to form the salt.

Given: - Mass of potassium hydroxide (KOH) = 7.8 g - Volume of water used = 200 g - Volume of carbon dioxide (CO2) = 2.24 L (at standard temperature and pressure)

To find the mass of salt, we can use the stoichiometry of the reaction between potassium hydroxide (KOH) and carbon dioxide (CO2). The balanced equation for the reaction is:

2 KOH + CO2 → K2CO3 + H2O

From the balanced equation, we can see that 2 moles of KOH react with 1 mole of CO2 to produce 1 mole of K2CO3.

To calculate the moles of KOH, we can use the formula:

moles = mass / molar mass

The molar mass of KOH is calculated as follows: - Molar mass of K = 39.1 g/mol - Molar mass of O = 16.0 g/mol - Molar mass of H = 1.0 g/mol

So, the molar mass of KOH = 39.1 + 16.0 + 1.0 = 56.1 g/mol

Using the given mass of KOH (7.8 g) and the molar mass of KOH (56.1 g/mol), we can calculate the moles of KOH:

moles of KOH = 7.8 g / 56.1 g/mol

Now, since the stoichiometric ratio between KOH and CO2 is 2:1, we can determine the moles of CO2 that reacted:

moles of CO2 = (moles of KOH) / 2

Finally, to calculate the mass of K2CO3 (salt), we can use the molar mass of K2CO3:

- Molar mass of K = 39.1 g/mol - Molar mass of C = 12.0 g/mol - Molar mass of O = 16.0 g/mol

So, the molar mass of K2CO3 = (39.1 * 2) + 12.0 + (16.0 * 3) = 138.1 g/mol

Using the moles of CO2 and the molar mass of K2CO3, we can calculate the mass of K2CO3:

mass of K2CO3 = (moles of CO2) * (molar mass of K2CO3)

Now let's perform the calculations:

1. Calculate the moles of KOH: - Moles of KOH = 7.8 g / 56.1 g/mol = 0.139 moles of KOH

2. Calculate the moles of CO2: - Moles of CO2 = (moles of KOH) / 2 = 0.139 moles of CO2

3. Calculate the mass of K2CO3: - Mass of K2CO3 = (moles of CO2) * (molar mass of K2CO3) = 0.139 moles * 138.1 g/mol = 19.17 g

Therefore, the mass of salt (K2CO3) in the formed solution is approximately 19.17 g.