When dT = Kf * molality * i
= Kf*m*i
and when molality = (no of moles of solute) / Kg of solvent
= 2.5g /250g x 1 mol /85 g x1000g/kg
=0.1176 molal
and Kf for water = - 1.86 and dT = -0.255
by substitution
0.255 = 1.86* 0.1176 * i
∴ i = 1.166
when the degree of dissociation formula is: when n=2 and i = 1.166
a= i-1/n-1 = (1.166-1)/(2-1) = 0.359 by substitution by a and c(molality) in K formula
∴K = Ca^2/(1-a)
= (0.1176 * 0.359)^2 / (1-0.359)
= 2.8x10^-3
Answer is: pH of ammonium hydroxide is 11.13.
Chemical reaction of ammonium hydroxide in water: NH₄OH → NH₄⁺ +
OH⁻<span>.
</span>
Kb(NH₄OH) = 1,8·10⁻⁵<span>.
c</span>₀(NH₄OH<span>) = 0.1 M.
c(NH</span>₄⁺) = c(OH⁻<span>) = x.
c(</span>NH₄OH<span>) = 0.1 M- x.
Kb = c(NH</span>₄⁺) · c(OH⁻) / c(NH₄OH<span>).
0,000018 = x² / 0.1 mol/L - x</span>.
Solve quadratic equation: x = c(OH⁻) = 0.00133 M.
pOH = -logc(OH⁻).
pOH = 2.87.
pH = 14 - 2.87.
pH = 11.13.
Answer:
We have to add 9.82 grams of calcium acetate
Explanation:
Step 1: Data given
Molarity of the calcium acetate solution = 0.207 M
Volume = 300 mL = 0.300 L
Molar mass calcium acetate = 158.17 g/mol
Step 2: Calculate moles calcium acetate
Moles calcium acetate = molarity * volume
Moles calcium acetate = 0.207 M * 0.300 L
Moles calcium acetate = 0.0621 moles
Step 3: Calculate mass calcium acetate
Mass calcium acetate = moles * molar mass
Mass calcium acetate = 0.0621 moles * 158.17 g/mol
Mass calcium acetate = 9.82 grams
We have to add 9.82 grams of calcium acetate
Answer:
See explanation
Explanation:
The principle of conservation of energy states that energy can neither be created nor destroyed but can be converted from one form to another. Hence, chemical energy in a battery can be converted to electrical energy.
Usually, the conversion of energy from one form to another is not 100% efficient according to the second law of thermodynamics. Some energy is wasted in the process, sometimes as heat.
Hence, in an ideal situation where no heat energy is produced; all the chemical energy is converted to electrical energy (100% energy conversion). There will be no energy loss if no heat is produced.
