Question

Помогите пожайлуста отдам 20 баллов:Вычислите относительную молекулярную массу веществ: а) S8; б) CO2; в) CH3COOH; г) Cl2; д) C2H2; ж) H2SiO3;

Answer 1

Ответ:

а) Mr(S₈) = 32·8 = 256

б) Mr(CO₂) =  12 +16·2 = 44

в) Mr(CH₃COOH) = 12+1·3+12+16+16+1 = 60

г) Mr(Cl₂) = 35,5·2=71

д) Mr(C₂H₂) = 12·2+1·2= 26

ж) Mr(H₂SiO₃) = 1·2+28+16·3=78

Answer 2

Calculation of Relative Molecular Mass

To calculate the relative molecular mass of a substance, we need to determine the sum of the atomic masses of all the atoms in its chemical formula. Here are the calculations for the given substances:

a) S8 (sulfur): - The atomic mass of sulfur (S) is approximately 32.07 g/mol. - Since there are 8 sulfur atoms in S8, the total mass is 32.07 g/mol * 8 = 256.56 g/mol.

b) CO2 (carbon dioxide): - The atomic mass of carbon (C) is approximately 12.01 g/mol. - The atomic mass of oxygen (O) is approximately 16.00 g/mol. - Since there is 1 carbon atom and 2 oxygen atoms in CO2, the total mass is 12.01 g/mol + (16.00 g/mol * 2) = 44.01 g/mol.

c) CH3COOH (acetic acid): - The atomic mass of carbon (C) is approximately 12.01 g/mol. - The atomic mass of hydrogen (H) is approximately 1.01 g/mol. - The atomic mass of oxygen (O) is approximately 16.00 g/mol. - Since there are 2 carbon atoms, 4 hydrogen atoms, and 2 oxygen atoms in CH3COOH, the total mass is (12.01 g/mol * 2) + (1.01 g/mol * 4) + (16.00 g/mol * 2) = 60.05 g/mol.

d) Cl2 (chlorine): - The atomic mass of chlorine (Cl) is approximately 35.45 g/mol. - Since there are 2 chlorine atoms in Cl2, the total mass is 35.45 g/mol * 2 = 70.90 g/mol.

e) C2H2 (acetylene): - The atomic mass of carbon (C) is approximately 12.01 g/mol. - The atomic mass of hydrogen (H) is approximately 1.01 g/mol. - Since there are 2 carbon atoms and 2 hydrogen atoms in C2H2, the total mass is (12.01 g/mol * 2) + (1.01 g/mol * 2) = 26.04 g/mol.

f) H2SiO3 (silicic acid): - The atomic mass of hydrogen (H) is approximately 1.01 g/mol. - The atomic mass of silicon (Si) is approximately 28.09 g/mol. - The atomic mass of oxygen (O) is approximately 16.00 g/mol. - Since there are 2 hydrogen atoms, 1 silicon atom, and 3 oxygen atoms in H2SiO3, the total mass is (1.01 g/mol * 2) + 28.09 g/mol + (16.00 g/mol * 3) = 78.11 g/mol.

Therefore, the relative molecular masses of the given substances are: - a) S8: 256.56 g/mol - b) CO2: 44.01 g/mol - c) CH3COOH: 60.05 g/mol - d) Cl2: 70.90 g/mol - e) C2H2: 26.04 g/mol - f) H2SiO3: 78.11 g/mol

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