The <span>modern-day quantum model of the atom known as the wave mechanical model depicts that the </span>electron was a three dimensional wave circling the nucleus in a whole number of
wavelengths allowing the waveform to repeat itself as a stable standing wave
(it can absorb energy form a nearby source which is oscillating at a proper
frequency) representing the energy levels of Bohr model.
Answer:
0.0010m SO₄²⁻
Explanation:
The freezing point depression due the addition of a solute into a pure solvent follows the equation:
ΔT = Kf×m×i (1)
<em>Where ΔT are °C that freezing point decreases (273.15K - 272.47K = 0.68K = 0.68°C). Kf is the constant of freezing point depression (1.86°C/m), m is molality of the solution (0.1778m) and i is Van't Hoff factor.</em>
Van't Hoff factor could be understood as in how many one mole of the solute (sulfuric acid, H₂SO₄), is dissociated.
H₂SO₄ dissociates as follows:
H₂SO₄ → HSO₄⁻ + H⁺
HSO₄⁻ ⇄ SO₄²⁻ + H⁺
<em>Not all HSO₄⁻ dissociates.</em>
1 Mole of H₂SO₄ dissociates in 1 mole of H⁺+ 1 mole of HSO₄⁻ + X moles of SO₄²⁻= 2 + X
Replacing in (1):
0.68°C = 1.86°C/m×0.1778m×i
2.056 = i
Moles of SO₄²⁻ are 2.056 - 2 = 0.056moles SO₄²⁻.
If 1 mole has a concentration of 0.1778m, 0.056moles are:
0.056moles ₓ (0.1778m / 1mole) =
<h3>0.0010m SO₄²⁻</h3>
Answer:
C. Energy is absorbed and released during chemical reactions,
Explanation:
All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. Endothermic reactions absorb energy, and exothermic reactions release energy.
Answer:
The piece of wood will sink
Explanation:
If an object has a density higher than water, it will sink, and the piece of wood is more dense than water when measured.
Answer:
114.23g
Explanation:
Mass = xg
Mole = 0.334 mol
Molar mass of Sucrose
(C = 12, H = 1, O = 16)
C12H22O11
(12×12)+(1×22)+(16×11)
144 + 22 + 176
342g/mol
Mass = No of mole × Molar mass
Mass = 0.334 × 342
Mass = 114.228
Mass ≈ 114.23g
