M (NaCl) = n × M = 3.75 × 58.5 =
219.375 g
M (NaCl) = 23 + 35.5 = 58.5 g/mol
Answer:
The Sun is the major source of energy for organisms and the ecosystems of which they are a part. Producers such as plants, algae, and cyanobacteria use the energy from sunlight to make organic matter from carbon dioxide and water. This establishes the beginning of energy flow through almost all food webs
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:
Empirical formula will be (NH₄)₃PO₄, which matches the molecular formula
Explanation:
This is the reaction:
NH₃ + H₃PO₄ → 28.2% N, 20.8% P, 8.1% H, 42.9% O
In 100 g of compound we have:
28.2 g N
20.8 g of P
8.1 g of H
42.9 g of O
Now we divide each between the molar mass:
28.2 g / 14 g/mol = 2.01 mol
20.8 g / 30.97 g/mol = 0.671 mol
8.1 g / 1 g/mol = 8.1 mol
42.9 g / 16 g/mol = 2.68 mol
And we divide again between the lowest value of moles
2.01 mol / 0.671 mol → 3
0.671 mol / 0.671 mol → 1
8.1 mol / 0.671 mol → 12
2.68 mol / 0.671 mol → 4
Molecular formula will be: N₃PH₁₂O₄ → (NH₄)₃PO₄
Empirical formula will be (NH₄)₃PO₄, which matches the molecular formula
29 protons, 34 neutrons, and if there is no charge there will be 29 electrons
