Question

Расчитайте массовые доли элеметов в корбанате калия .

Answer 1

М(К2СО3)=138г/моль

W=Ar*n/M

W(К2)=39*2.138=56,5%

W(C)=12/138=8%

W(О)=100%-(56,5+8)=35,5%

Answer 2

Calculation of Mass Fractions in Potassium Carbonate

To calculate the mass fractions of elements in potassium carbonate (K2CO3), we need to determine the molar masses of each element and the compound as a whole.

The molar mass of an element is the mass of one mole of that element, expressed in grams per mole (g/mol). The molar mass of a compound is the sum of the molar masses of its constituent elements.

Let's calculate the mass fractions of potassium (K), carbon (C), and oxygen (O) in potassium carbonate.

1. Molar Mass of Potassium (K): The atomic mass of potassium (K) is approximately 39.10 g/mol Since there are two potassium atoms in potassium carbonate (K2CO3), the molar mass of potassium in the compound is: 2 * 39.10 g/mol = 78.20 g/mol

2. Molar Mass of Carbon (C): The atomic mass of carbon (C) is approximately 12.01 g/mol There is only one carbon atom in potassium carbonate (K2CO3), so the molar mass of carbon in the compound is: 1 * 12.01 g/mol = 12.01 g/mol

3. Molar Mass of Oxygen (O): The atomic mass of oxygen (O) is approximately 16.00 g/mol There are three oxygen atoms in potassium carbonate (K2CO3), so the molar mass of oxygen in the compound is: 3 * 16.00 g/mol = 48.00 g/mol

4. Total Molar Mass of Potassium Carbonate (K2CO3): The total molar mass of potassium carbonate is the sum of the molar masses of potassium, carbon, and oxygen: 78.20 g/mol (K) + 12.01 g/mol (C) + 48.00 g/mol (3 * O) = 138.21 g/mol

Now, let's calculate the mass fractions of each element in potassium carbonate.

1. Mass Fraction of Potassium (K): The mass fraction of potassium is the mass of potassium divided by the total mass of the compound, multiplied by 100%: (78.20 g/mol / 138.21 g/mol) * 100% = 56.57%

2. Mass Fraction of Carbon (C): The mass fraction of carbon is the mass of carbon divided by the total mass of the compound, multiplied by 100%: (12.01 g/mol / 138.21 g/mol) * 100% = 8.69%

3. Mass Fraction of Oxygen (O): The mass fraction of oxygen is the mass of oxygen divided by the total mass of the compound, multiplied by 100%: (48.00 g/mol / 138.21 g/mol) * 100% = 34.74%

Therefore, the mass fractions of elements in potassium carbonate (K2CO3) are approximately: - Potassium (K): 56.57% - Carbon (C): 8.69% - Oxygen (O): 34.74%

Please note that these values are approximate and may vary slightly depending on the source and the level of precision used in the atomic masses.

I hope this helps! Let me know if you have any further questions.