Question

рассчитайте массовые доли каждого из элементов в веществах:а)углекислом газе СО2"б)сульфиде кальцияСаS.Пожалйста решитте оочень надоо!!!

Answer 1

а)w(C)=12/44*100%=27,2%

w(O2)=32/44*100%=72,8%

б)w(Ca)=40/72*100%=55,5%

w(S)=32/72*100%=44,5%

Answer 2

Calculation of Mass Fractions in Substances

To calculate the mass fractions of each element in a substance, we need to know the molar masses of the elements and the compound's molecular formula. Let's calculate the mass fractions for carbon dioxide (CO2) and calcium sulfide (CaS).

a) Carbon Dioxide (CO2)

The molecular formula of carbon dioxide is CO2. To calculate the mass fractions, we need to determine the molar masses of carbon (C) and oxygen (O) and then use the formula:

Mass Fraction = (Molar Mass of Element / Molar Mass of Compound) x 100%

The molar mass of carbon (C) is approximately 12.01 g/mol, and the molar mass of oxygen (O) is approximately 16.00 g/mol. The molar mass of carbon dioxide (CO2) can be calculated as follows:

Molar Mass of CO2 = (Molar Mass of C) + 2 x (Molar Mass of O) = (12.01 g/mol) + 2 x (16.00 g/mol) = 12.01 g/mol + 32.00 g/mol = 44.01 g/mol

Now, let's calculate the mass fractions of carbon and oxygen in carbon dioxide:

Mass Fraction of Carbon (C) = (Molar Mass of C / Molar Mass of CO2) x 100%

Mass Fraction of Carbon (C) = (12.01 g/mol / 44.01 g/mol) x 100% = 0.2729 x 100% ≈ 27.29%

Mass Fraction of Oxygen (O) = (2 x Molar Mass of O / Molar Mass of CO2) x 100%

Mass Fraction of Oxygen (O) = (2 x 16.00 g/mol / 44.01 g/mol) x 100% = 0.7271 x 100% ≈ 72.71%

Therefore, in carbon dioxide (CO2), the mass fraction of carbon (C) is approximately 27.29%, and the mass fraction of oxygen (O) is approximately 72.71% [[1]].

b) Calcium Sulfide (CaS)

The molecular formula of calcium sulfide is CaS. To calculate the mass fractions, we need to determine the molar masses of calcium (Ca) and sulfur (S) and then use the formula mentioned earlier.

The molar mass of calcium (Ca) is approximately 40.08 g/mol, and the molar mass of sulfur (S) is approximately 32.07 g/mol. The molar mass of calcium sulfide (CaS) can be calculated as follows:

Molar Mass of CaS = (Molar Mass of Ca) + (Molar Mass of S) = 40.08 g/mol + 32.07 g/mol = 72.15 g/mol

Now, let's calculate the mass fractions of calcium and sulfur in calcium sulfide:

Mass Fraction of Calcium (Ca) = (Molar Mass of Ca / Molar Mass of CaS) x 100%

Mass Fraction of Calcium (Ca) = (40.08 g/mol / 72.15 g/mol) x 100% = 0.5552 x 100% ≈ 55.52%

Mass Fraction of Sulfur (S) = (Molar Mass of S / Molar Mass of CaS) x 100%

Mass Fraction of Sulfur (S) = (32.07 g/mol / 72.15 g/mol) x 100% = 0.4448 x 100% ≈ 44.48%

Therefore, in calcium sulfide (CaS), the mass fraction of calcium (Ca) is approximately 55.52%, and the mass fraction of sulfur (S) is approximately 44.48% [[2]].

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