Question

Определите валентность элементов P2O5, NO2, N2O5, Cr2O3, SiO2, B2O3, SiH4, Mn2O7, MnO, CuO, N2O3.Вычислите молекулярную массу веществP2O5, NO2, N2O5, Cr2O3, SiO2, B2O3, SiH4, Mn2O7, MnO, CuO, N2O3.​

Answer 1

Ответ:

Объяснение:

1) P(V)O(II),  N(IV)O(II),  N(V)O(II),  Cr(III)O(II),  Si(IV)O(II),  B(III)O(II),  Si(IV)H(I),  Mn(VII)O(II),  Mn(II)O(II),  Cu(II)O(II),  N(III)O(II)

2) Mr(P2O5) = 31*2 + 16*5 = 142

Mr(NO2) = 14 + 16*2 = 46

Mr(N2O5) = 14*2 + 16*5 = 108

Mr(Cr2O3) = 52*2 + 16*3 = 152

Mr(SiO2) = 28 + 16*2 =60

Mr(B2O3) = 11*2 + 16*3 =70

Mr(SiH4) = 28 + 1*4 = 32

Mr(Mn2O7) = 55*2 + 16*7 =222

Mr(MnO) = 55 + 16 = 71

Mr(CuO) = 64 +16 = 80

Mr(N2O3) = 14*2 + 16*3 =76

Answer 2

Valency of Elements and Calculation of Molecular Mass

Valency of Elements:

- P2O5: The valency of phosphorus (P) is typically +3 or -3, and the valency of oxygen (O) is -2. In P2O5, the valency of phosphorus is +5, and the valency of oxygen is -2.

- NO2: The valency of nitrogen (N) is typically -3, -2, +3, +4, or +5, and the valency of oxygen (O) is -2. In NO2, the valency of nitrogen is +4, and the valency of oxygen is -2.

- N2O5: The valency of nitrogen (N) is typically -3, -2, +3, +4, or +5, and the valency of oxygen (O) is -2. In N2O5, the valency of nitrogen is +5, and the valency of oxygen is -2.

- Cr2O3: The valency of chromium (Cr) is typically +2, +3, or +6, and the valency of oxygen (O) is -2. In Cr2O3, the valency of chromium is +3, and the valency of oxygen is -2.

- SiO2: The valency of silicon (Si) is typically +4, and the valency of oxygen (O) is -2. In SiO2, the valency of silicon is +4, and the valency of oxygen is -2.

- B2O3: The valency of boron (B) is typically +3, and the valency of oxygen (O) is -2. In B2O3, the valency of boron is +3, and the valency of oxygen is -2.

- SiH4: The valency of silicon (Si) is typically +4, and the valency of hydrogen (H) is +1. In SiH4, the valency of silicon is +4, and the valency of hydrogen is +1.

- Mn2O7: The valency of manganese (Mn) is typically +2, +4, +6, or +7, and the valency of oxygen (O) is -2. In Mn2O7, the valency of manganese is +7, and the valency of oxygen is -2.

- MnO: The valency of manganese (Mn) is typically +2, +4, +6, or +7, and the valency of oxygen (O) is -2. In MnO, the valency of manganese is +2, and the valency of oxygen is -2.

- CuO: The valency of copper (Cu) is typically +1 or +2, and the valency of oxygen (O) is -2. In CuO, the valency of copper is +2, and the valency of oxygen is -2.

- N2O3: The valency of nitrogen (N) is typically -3, -2, +3, +4, or +5, and the valency of oxygen (O) is -2. In N2O3, the valency of nitrogen is +3, and the valency of oxygen is -2.

Molecular Mass Calculation:

The molecular masses of the substances can be calculated by adding the atomic masses of the constituent elements in the chemical formula.

- P2O5: Phosphorus (P) has an atomic mass of approximately 30.97 g/mol, and oxygen (O) has an atomic mass of approximately 16.00 g/mol. Therefore, the molecular mass of P2O5 is approximately 141.94 g/mol.

- NO2: Nitrogen (N) has an atomic mass of approximately 14.01 g/mol, and oxygen (O) has an atomic mass of approximately 16.00 g/mol. Therefore, the molecular mass of NO2 is approximately 46.01 g/mol.

- N2O5: The molecular mass of N2O5 can be calculated similarly by adding the atomic masses of nitrogen and oxygen.

- Cr2O3: The molecular mass of Cr2O3 can be calculated similarly by adding the atomic masses of chromium and oxygen.

- **SiO2