27/208 = normality
12 x 10^-2 approx = normality
nw Ka = 14.3 x 10^-3
pKa = 3 - log 14
now, after getting the pKa put it in formula :
pH = pKa + log concn of ion/concn of salt and you'll get it
hope this helps
Answer:
(i) Bohr; (ii) de Broglie; (iii) Heisenberg (v) Schrödinger
Explanation:
(i) Niels Bohr — 1913 — proposed that electrons travel in fixed orbits with <em>quantized energy levels</em> and that they jump from one energy level to another by absorbing or emitting quanta of light.
(ii) <em>Louis de Broglie</em> — 1924 — proposed the wave nature of electrons and suggested that all matter behaves as both waves and particles (<em>wave-particle duality</em>).
(iii) Werner Heisenberg — 1927 — formulated quantum mechanics in terms of matrices and proposed his famous <em>uncertainty principle</em>.
(v) Erwin Schrödinger — 1926 — applied wave mechanics to the electron in a hydrogen atom, showing that electrons exist in <em>orbitals </em>rather that orbits.
(iv) <em>Ernest Rutherford</em> — 1911 — proposed that atoms have most of their mass in a central nucleus (<em>nuclear atom</em>). Quantum mechanics had not yet been invented.
Answer:107.1 g, 124.1 g
Explanation:
The equation of the reaction is;
Al2S3(s) + 6H20(l) ----> 2Al(OH)3(s) + 3H2S(g)
Hence;
For Al2S3
Number of moles= reacting mass/molar mass
Number of moles = 158g/150gmol-1 =1.05 moles
If 1 mole of Al2S3 yields 3 moles of H2S
1.05 moles of Al2S will yield
1.05 × 3/1 = 3.15 moles
Mass of H2S = 3.15moles × 34 gmol-1 = 107.1 g
For water
Number of moles of water = 131g/18gmol-1= 7.3 moles
6 moles of water yields 3 moles of H2S
7.3 moles of water will yield 7.3 × 3/6 = 3.65 moles of H2S
3.65 moles × 34 gmol-1 =124.1 g
Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal.
First, lets balance the reaction equation:
4Fe + 3O₂ → 2Fe₂O₃
It is visible form the equation that 4 moles of Fe require 3 moles of O₂
Molar ratio Fe/O₂ = 4/3 = 1.33
Molar ratio O₂/Fe = 3/4 = 0.75
Now, we check the molar ratios present:
Fe/O₂ = 6.8/8.9 = 0.76
O₂/Fe = 1.31
Thus, Iron is the limiting reactant because its ratio is not being fulfilled while the ratio of O₂ is surpassed.
