Answer:
C. NaHCO3 → Na2CO3 + H2O + CO2
Explanation:
» For a balanced equation, the number of atoms of reactants and products must be equal.
» In equation C, the reactant side has one sodium atom while ptoduct side has 2 sodium atoms.
» The balanced equations mus be;
To calculate the pH of this solution, we use the
Henderson-Hasselbalch equation:
pH = pKa + log ([A-]/[HA])
Where,
[A-] = Molarity of the conjugate base =
CH3COO- = 0.29 M<span>
<span>[HA] = Molarity of the weak acid = CH3COOH = 0.18 M</span></span>
pKa = dissociation constant of the weak acid =
4.75
When KOH is added to the buffer, the chemical
reaction is:
CH3COOH + KOH = CH3COO-K+ + H2O
Therefore when 0.0090 mol KOH is added, 0.0090
mol acid is neutralized, and 0.0090 mol CH3COO- is produced.
[CH3COO-] = [0.0090 mol + 0.375 L (0.29 mol/L) ]
/ 0.375 L = 0.314 M
[CH3COOH] = [-0.0090 mol + 0.375 L (0.18 mol/L) ]
/ 0.375 L = 0.156 M
Going back to Henderson-Hasselbalch
equation:
pH = 4.75 + log (0.314 / 0.156)
<span>pH = 5.054</span>
Answer:
3 electrons are gained by one nitrogen atom in the formation of K₃N.
Explanation:
The reaction is as follow,
<span> 6 K + N</span>₂<span> </span>→ <span> 2 K</span>₃<span>N
</span>
Oxidation of K,
K → K⁺ + 1 e⁻
Or,
6 K → 6 K⁺ + 6 e⁻
In oxidation reaction potassium atom transfers one electron per atomn and six electrons per six atoms.
Reduction of N;
N₂ + 6 e⁻ → 2 N³⁻
In reduction reaction one molecule of N₂ gains six electrons and 3 electrons per one atom
Answer is: the pressure in a vessel is 1.48 atm.
V(Cl₂) = 22.4 L; pressure of chlorine gas.
n(Cl₂) = 1.50 mol; amount of chlorine gas.
T = 0.00°C = 273.15 K; temperature.
a = 6.49 L²·atm/mol²; the constant a provides a correction for the intermolecular forces.
b = 0.0562 L/mol; value is the volume of one mole of the chlorine gas.
R = 0.08206 L·atm/mol·K, universal gas constant.
Van de Waals equation: (P + an² / V²)(V - nb) = nRT.
(P + 6.49 L²·atm/mol² · (1.5 mol)² / (22.4 L)²) · (22.4 L - 1.5 mol·0.0562 L/mol) = 1.5 mol · 0.08206 L·atm/mol·K · 273.15 K.
(P + 6.49 L²·atm/mol² · (1.5 mol)² / (22.4 L)²) = (1.5 mol · 0.08206 L·atm/mol·K · 273.15 K) ÷ (22.4 L - 1.5 mol · 0.0562 L/mol).
P + 0.029 atm = 33.62 L·atm ÷ 22.31 L.
P = 1.507 atm - 0.029 atm.
P = 1.48 atm; the pressure.
