Number of moles:
n = sample mass / molar mass
n = 15.00 / 74.6
n = 0.2010 moles of KCl
Therefore:
Molarity = moles / Volume
0.1107 = 0.2010 / V
V = 0.2010 / 0.1107
V = 1.815 L
Answer:
Energy is neither created nor destroyed.
Explanation:
The law of conservation of energy states that energy can neither be created nor be destroyed. The total energy of an isolated system remains conserved. It never gets 0. It changes from one form of energy to other but never vanishes.
Hence, the correct option is (d) "Energy is neither created nor destroyed"
Answer:
final concentration: Ca = 0.014 M
Explanation:
Velocity of reaction:
∴ α: order of reaction, assuming α = 1
∴ K = 0.249 s-1.......rate constant
∴ Cao = 0.050 M......initial concentration
∴ t = 5 s.......reaction time
⇒ δCa/δt = K*Ca
⇒ ∫δCa/Ca = K*∫δt
⇒ Ln(Cao/Ca) = K*t = (0.249s-1)(5 s) = 1.245
⇒ Cao/Ca = 3.473
⇒ Ca = 0.050/3.473
⇒ Ca = 0.014 M
First, we determine the energy released by the reaction using the heat capacity and change in temperature as such:
Q = cΔT
Q = 32.16 * 0.42
Q = 13.51 kJ
Next, we determine the moles of ammonia formed as the heat of formation is expressed in "per mole".
Moles = mass / molecular weight
Moles = 5/17
Moles = 0.294
Heat of formation = 13.51 / 0.294
The heat of formation of ammonia is 45.95 kJ/mol
Answer:
Explanation:
By the First Law of Thermodynamics, the piece of metal and water reaches thermal equilibrium when water receives heat from the piece of metal. Then:
