D(O₂)=2,25
D(O₂) = Mr(CnH2n+2)÷Mr(O₂)
Mr(CnH2n+2)=D(O₂) xMr(O₂)
M(CnH2n+2)=2,25 x 32=72
CnH2n+2 =72
12n+2n +2=72
14n=72-2
n=70÷14=5
Формула вещества: C₅H₁₂
925 проба- это массовая доля серебра 92,5\%=0,925
A) 2СH4 = C2H2 + 3H2 (t=1500C)
C2H2 + H2O = CH3CHO (Hg2+, H+)
CH3CHO + H2 = C2H5OH
C2H5OH + HBr = C2H5Br + H2O
C2H5Br + KOH(спиртовой) = С2H4 + KBr + H2O
C2H4 + H2O = C2H5OH (H2SO4)
3C2H5OH + 4H2SO4 + K2Cr2O7 = 3CH3CHO + 2KCr(SO4)2 + 7H2O
б) CH4 + O2 = 2HCOH (t, кат.)
HCOH + H2 = CH3OH
CH3OH + HCl = CH3Cl + H2O
2CH3Cl + 2Na = C2H6 + 2NaCl
C2H6 + O2 = C2H5OH (t, кат.)
<span>5C2H5OH+4KMnO4+6H2SO4=5CH3COOH+4MnSO4+2K2SO4+11H2O </span>
H₂SO₄ + 2NaOH = Na₂SO₄ + 2H₂O
2H⁺ + SO₄²⁻ + 2Na⁺ +2OH⁻ = 2Na⁺ + SO₄²⁻ + 2H₂O
2H⁺ +2OH⁻ = 2H₂O
([MnO2]*n(MnO4-)*x(Na+))*(n-x)(Na+)
Вроде так.