Answer: 
.
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
(2)
The final reaction is:
(3)
By adding (1) and (2)
Hence .
Answer:
14 ft 7 inches
step-by-step explanation:
since each model inch corresponds to 25 real inches, 7 model inches will correspond to
7×25" = 175"
at 12" per foot, that is 14 feet, 7 inches.
Explanation:
Chemical change. You can never get back the rusted layers of metal even though you can wipe off the rust. Chemical changes are irreversible.
Answer:
Q = 63.75J
Explanation:
Mass = 2.5g
Initial temperature (T1) = 25°C
Final temperature (T2) = 50°C
Specific heat capacity of Mg = 1.020J/g°C
Heat energy = ?
Heat Energy (Q) = mc∇T
Q = heat energy
M = mass of substance
C = specific heat capacity of substance
∇T = change in temperature = T2 - T1
Q = mc∇T
Q = mc(T2 - T1)
Q = 2.5 × 1.020 × (50 - 25)
Q = 2.55 × 25
Q = 63.75J
The heat energy required to raise magnesium metal from 25°C to 50°C is 63.75J
Answer:
8.08 × 10⁻⁴
Explanation:
Let's consider the following reaction.
COCl₂(g) ⇄ CO (g) + Cl₂(g)
The initial concentration of phosgene is:
M = 2.00 mol / 1.00 L = 2.00 M
We can find the final concentrations using an ICE chart.
COCl₂(g) ⇄ CO (g) + Cl₂(g)
I 2.00 0 0
C -x +x +x
E 2.00 -x x x
The equilibrium concentration of Cl₂, x, is 0.0398 mol / 1.00 L = 0.0398 M.
The concentrations at equilibrium are:
[COCl₂] = 2.00 -x = 1.96 M
[CO] = [Cl₂] = 0.0398 M
The equilibrium constant (Keq) is:
Keq = [CO].[Cl₂]/[COCl₂]
Keq = (0.0398)²/1.96
Keq = 8.08 × 10⁻⁴
