Answer:
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer. Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al2O3), the rest being a mixture of silica, various iron oxides, and titanium dioxide.
Strength of the magnetic field can be increased by:
1) increasing the current in the coil.
2) increasing the number of coils in the solenoid; and.
3) using a soft iron core within the solenoid.
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The original sample was a compound because it was composed of two different elements and was not purely one element
Answer:
-3.82ºC is the freezing point of solution
Explanation:
We work with the Freezing point depression to solve the problem
ΔT = m . Kf . i
ΔT = Freezing point of pure solvent - freezing point of solution
Let's find out m, molality (moles of solute in 1kg of solvent)
15 g / 58.45 g/mol = 0.257 moles of NaCl
NaCl(s) → Na⁺ (aq) + Cl⁻(aq)
i = 2 (Van't Hoff factor, numbers of ions dissolved)
m = mol /kg → 0.257 mol / 0.250kg = 1.03 m
Kf = Cryoscopic constant → 1.86 ºC/m (pure, for water)
0ºC - Tºf = 1.03m . 1.86ºC/m . 2
Tºf = -3.82ºC
The neutralization reaction goes according to the scheme
H⁺ + OH⁻ = H₂O
acid and base react, salt and water are formed
NaOH + HNO₃ = NaNO₃ + H₂O
2KOH + H₂SO₄ = K₂SO₄ + 2H₂O
