SODIUM SULFIDE Na2SProperties of sodium sulfide Na2S: White, melts without decomposition, heat-resistant. Anhydrous Na2S powder is pyrophoric in dry air. Readily soluble in water (strong hydrolysis on the anion). High reactivity, in moist state oxidized by oxygen of air, attaches sulfur. Decomposes by acids. Typical reductant.
Obtaining sodium sulfide Na2S: 2 Na + E = Na2E (t > 130° С, E = S, Se, Те) 2 Na + nS = Na2(Sn) (-40° С, in the liquid NH3, n = 1, 2, 4, 5). Na2SO4 + 4H2 = Na2S + 4H2O (550-600°C, catalyst Fe2O3). H2S + NaOH (diluted) = NaHS + H2O H2S + 2NaOH (diluted) = Na2S + 2H2O. Reactions with sodium sulfide Na2S: Na2S·9H2O = Na2S + 9H2O (15-35°C; conc. H2SO4, P4O10). Na2S (diluted) + 8H2O = 2[Na(H2O)4](+) + S(2-). S(2-) + H2O ↔ HS(-) + OH(-). Na2S + 2HCl (diluted) = 2NaCl + H2S↑. Na2S + 3H2SO4 (diluted) = 2NaHSO4 + SO2↑ + S↓ + 2H2O Na2S + 4HNO3 (diluted) = 2NaNO3 + 2NO2↑ + S↓ + 2H2O. Na2S (solution) + NaOH → O2(air), solid S(colloid), Na2Sn. Na2SO3S + Na2S (solid) + 2O2 = Na2SO4 (t > 400°C) Na2S + H2S (saturated.) = 2NaHS. Na2S (solution) + (n - 1)S = Na2(S4) [boiling]. Na2S + S = Na2(S2) (600°C). Na2S + 3S = Na2(S4) (400°C). Na2S + 4S = Na2(S5) (200°C). Na2S + CaCO3 = Na2CO3 + CaS (1200°C). Na2S (diluted) + Na2SO3 (diluted) + I2 = Na2SO3S + 2 NaI. Na2S + 4H2O2 (conc.) = Na2SO4 + 4H2O. |
Did you know?
Ionic radius of non-metals are larger than their atomic radius (gain electrons.)