1) Chemical reaction: HCN + H₂O → CN⁻ + H₃O⁺.
c(HCN) = 2,2 M = 2,2 mol/L.
pKa(HCN) = 9,21.
Ka = 6,16·10⁻¹⁰.
[CN⁻] = [H₃O⁺] = x.
[HCN<span>] = 2,2 M - x.
</span>Ka = [CN⁻] · [H₃O⁺] / [HCN].
6,16·10⁻¹⁰ = x² / 2,2 M -x.
Solve quadratic equation: [CN⁻] = [H₃O⁺] = 0,0000346 M.
[HCN] = 2,2 M - 0,0000346 M = 2,199 M.
2) pH = - log[H₃O⁺].
pH = -log( 0,0000346 M).
pH = 4,46.
Hydrocyanic acid and hydronium ion (H₃O⁺) are acids. Cyanide anion (CN⁻) is the strongest base in the system, cyanide anion accept protons in chemical reaction.
pKb = pKw - pKa.
pKb = 14 - 9,21 = 4,79.
Answer:
NO will be the limiting reagent.
Explanation:
The balanced equation is:
2 NO + 2 CO → N₂ + 2 CO₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
- NO: 2 moles
- CO: 2 moles
- N₂: 1 mole
- CO₂: 2 moles
Being the molar mass of each compound:
- NO: 30 g/mole
- CO: 28 g/mole
- N₂: 28 g/mole
- CO₂: 44 g/mole
Then by stoichiometry the following quantities of mass participate in each reaction:
- NO: 2 moles* 30 g/mole= 60 g
- CO: 2 moles* 28 g/mole= 56 g
- N₂: 1 mole* 28 g/mole= 28 g
- CO₂: 2 moles* 44 g/mole= 88 g
The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
To determine the limiting reagent, you can use a simple rule of three as follows: If 56 grams of CO react with 60 grams of NO, 3 grams of CO react with how much mass of NO?
mass of NO= 3.21 grams
But 3.21 grams of NO are not available, 3 grams are available. Since you have less moles than you need to react with 3 grams of CO, <u><em>NO will be the limiting reagent.
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Hmmmm i understand but i wanna know what to measure or whats about?
The volume of I- is missing in your question by assuming it = 1L
moles I- = molarity * volume
= 0.00237 * 1 L
= 0.00237 mol
[I-] = moles / total volume
= 0.00237 / 1.625L
= 0.00146 M
moles Pb2+ = molarity * volume
= 0.00785 * 0.625 L
= 0.0049 mol
[Pb2+] = 0.0049 / 1.625L
= 0.003 M
when PbI2(s) ↔ Pb2+(aq) + 2I-(aq)
when Q = [Pb2+][I-]^2 and we neglect [PbI2] as it is solid
∴ Q = 0.003 * (0.00146)^2
= 6.4 x 10^-9
by comparing the value of Q with Ksp value we will found that:
Q < Ksp which mean that more solid will dissolve, and this is an unsaturated solution which has ion concentrations < equilibrium concentrations, so the reaction will go forward until achieving equilibrium.
Answer:
C₂H₃O
Explanation:
From the question given above, the following data were obtained:
Carbon (C) = 48.8383%
Hydrogen (H) = 8.1636%
Oxygen (O) = 43.1981%
Empirical formula =?
The empirical formula of the compound can be obtained as follow:
C = 48.8383%
H = 8.1636%
O = 43.1981%
Divide by their molar mass
C = 48.8383 / 12 = 4.07
H = 8.1636 / 1 = 8.1636
O = 43.1981 / 16 = 2.7
Divide by the smallest
C = 4.07 / 2.7 = 2
H = 8.1636 / 2.7 = 3
O = 2.7 /2.7 = 1
Thus, the empirical formula of the compound is C₂H₃O
