Question

Вычислите массовые доли элементов (в процентах):а)в оксиде серы(4 валентность),б)в бертолетовой соли КСlO3

Answer 1

1)w(S)=32/64*100=50%
w(O)=16*2/64=50%
2)w(K)=39/122,5*100=31,83%
w(Cl)=35,5/122,5=28,97%
w(O)=16*3/122,5*100=39,18%

Answer 2

Calculating Mass Percentages of Elements

a) For the oxide of sulfur (with a valency of 4): The molecular formula for sulfur oxide is SO2. To calculate the mass percentages of elements in sulfur oxide, we can use the molar masses of sulfur (S) and oxygen (O).

The molar mass of Sulfur (S) = 32.07 g/mol The molar mass of Oxygen (O) = 16.00 g/mol

Using the molecular formula (SO2), we can calculate the mass percentages of Sulfur and Oxygen in the compound.

Sulfur (S) mass percentage: = (Mass of Sulfur / Molar mass of SO2) * 100 = (32.07 / (32.07 + 2*16.00)) * 100 = (32.07 / 64.07) * 100 = 50.1%

Oxygen (O) mass percentage: = (Mass of Oxygen / Molar mass of SO2) * 100 = (2*16.00 / (32.07 + 2*16.00)) * 100 = (32.00 / 64.07) * 100 = 49.9%

Therefore, the mass percentages of Sulfur and Oxygen in the oxide of sulfur (with a valency of 4) are approximately 50.1% and 49.9% respectively.

b) For Bertollet's salt KClO3: The molecular formula for Bertollet's salt is KClO3. To calculate the mass percentages of elements in Bertollet's salt, we can use the molar masses of potassium (K), chlorine (Cl), and oxygen (O).

The molar mass of Potassium (K) = 39.10 g/mol The molar mass of Chlorine (Cl) = 35.45 g/mol The molar mass of Oxygen (O) = 16.00 g/mol

Using the molecular formula (KClO3), we can calculate the mass percentages of Potassium, Chlorine, and Oxygen in the compound.

Potassium (K) mass percentage: = (Mass of Potassium / Molar mass of KClO3) * 100 = (39.10 / (39.10 + 35.45 + 3*16.00)) * 100 = (39.10 / 122.55) * 100 = 31.9%

Chlorine (Cl) mass percentage: = (Mass of Chlorine / Molar mass of KClO3) * 100 = (35.45 / (39.10 + 35.45 + 3*16.00)) * 100 = (35.45 / 122.55) * 100 = 28.9%

Oxygen (O) mass percentage: = (Mass of Oxygen / Molar mass of KClO3) * 100 = (3*16.00 / (39.10 + 35.45 + 3*16.00)) * 100 = (48.00 / 122.55) * 100 = 39.2%

Therefore, the mass percentages of Potassium, Chlorine, and Oxygen in Bertollet's salt KClO3 are approximately 31.9%, 28.9%, and 39.2% respectively