Question

In: Mechanical Engineering

Is the relation "delta h(enthalpy) = m * Cp,avg * delta T" restricted to constant pressure...

Is the relation "delta h(enthalpy) = m * Cp,avg * delta T" restricted to constant pressure process only, or can it be used for any kind of process of an ideal gas? detailed and easy-to-understand reason included, please.

Solutions

Expert Solution

This relation can be uswed to determine the enthalpy change for any gas (real or ideal), undergoing a constant pressure process. however, if the gas is ideal, this equation can be used to determine the enthalpy change of the gas irrespective of the process that it is undergoing.

Reason:

generally, the enthalpy change is a function of temperature and pressure. i.e.

therefore,

using the maxwell's equation and the defination of specific heat, the equation transforms into

so for any constant pressure process, dP=0, therefore equation just becomes:

however, let an ideal gas undergo any process which is not constant pressure.

for an ideal gas, we know:

and,

hence,


Related Solutions

Is the relation "delta h(enthalpy) = m * Cp,avg * delta T" restricted to constant pressure...
Is the relation "delta h(enthalpy) = m * Cp,avg * delta T" restricted to constant pressure process only, or can it be used for any kind of process of an ideal gas? detailed and easy-to-understand reason included, please.
M (g)   M (kg)   Delta t1(s)   Delta t2(s)   Delta t3(s)   Delta t(s) avg.   T (s)   T2...
M (g)   M (kg)   Delta t1(s)   Delta t2(s)   Delta t3(s)   Delta t(s) avg.   T (s)   T2 (s2)   60 0.06 6.53 6.55 6.31 6.46 0.646 0.42 80 0.08 6.63 6.60 6.64 6.62 0.662 0.44 100 0.10 6.99 6.87 7.08 6.98 0.698 0.49 120 0.12 8.12 8.36 8.46 8.31 0.831 0.69 140 0.14 8.35 8.11 8.15 8.20 0.820 0.67 find the slope (4pi^2)/k calculate the intercept ((4pi^2)/3k)m Equate the value of the slope found at point 5 with (4pi^2)/k and solve for...
heat capacity at constant pressure Cp=(dH/dT) the difference between H(enthalpy) and U(internal energy) is PdV=RT(in perfect...
heat capacity at constant pressure Cp=(dH/dT) the difference between H(enthalpy) and U(internal energy) is PdV=RT(in perfect gas) Then, in real gas, how can I know the difference?
Enthalpy H is a measure of the energy content of a system at constant pressure. Chemical...
Enthalpy H is a measure of the energy content of a system at constant pressure. Chemical reactions involve changes in enthalpy, ΔH, which can be measured and calculated: ΔHrxn∘=∑productsmΔHf∘−∑reactantsnΔHf∘ where the subscript "rxn" is for "enthalpy of reaction" and "f" is for "enthalpy of formation" and m and n represent the appropriate stoichiometric coefficients for each substance. The following table lists some enthalpy of formation values for selected substances. Substance ΔHf∘ (kJ/mol) NaOH(aq) −469.1 MgCl2(s) −641.8 NaCl(aq) −407.3 Mg(OH)2(s) −924.5...
Calculate the change of enthalpy for: 4S + 6O2= 4SO3 Delta H= ___ kJ
Calculate the change of enthalpy for: 4S + 6O2= 4SO3 Delta H= ___ kJ
In a constant‑pressure calorimeter, 55.0 mL of 0.820 M H 2 SO 4 was added to...
In a constant‑pressure calorimeter, 55.0 mL of 0.820 M H 2 SO 4 was added to 55.0 mL of 0.360 M NaOH . The reaction caused the temperature of the solution to rise from 23.45 ∘ C to 25.90 ∘ C. If the solution has the same density and specific heat as water ( 1.00 g / mL and 4.184 J / ( g ⋅ °C), respectively), what is Δ H for this reaction (per mole of H 2 O...
In a constant‑pressure calorimeter, 60.0 mL of 0.920 M H 2 SO 4 was added to...
In a constant‑pressure calorimeter, 60.0 mL of 0.920 M H 2 SO 4 was added to 60.0 mL of 0.360 M NaOH . The reaction caused the temperature of the solution to rise from 22.43 ∘ C to 24.88 ∘ C. If the solution has the same density and specific heat as water ( 1.00 g / mL and 4.184 J / ( g ⋅ °C), respectively), what is Δ H for this reaction (per mole of H 2 O...
1. A chemical reaction at 304 K has an enthalpy change (delta-H) of -73.9 kJ/mol and...
1. A chemical reaction at 304 K has an enthalpy change (delta-H) of -73.9 kJ/mol and an entropy change (delta-S) of 161.6 kJ/mol. What is its Gibbs energy change, delta-G, in kJ/mol? Give the answer to one decimal place. 2.Use the thermodynamic data in your textbook to determine the temperature below which the following reaction is spontaneous. (Give the temperature in K, to the nearest degree.) 2SO2 (g) + O2 (g) -- 2SO3 (g) 3.What is the delta-G for the...
A process is carried out at constant pressure. Given that ∆E is positive and ∆H is negative,
A process is carried out at constant pressure. Given that ∆E is positive and ∆H is negative, D) the system loses heat and contracts during the process Which equation represents the reaction that corresponds to the standard enthalpy of formation b of CHCl3 at 25° (∆Hf of CHCl3)?C) 2 C(s) +H2(g) +3Cl2(g) ---> 2CHCl3(l) The reaction 4 Ag(s) +O2(g) ---->2AgO(s) favors Ag2O at low temperature, but it favors Ag and O2 at high temperatures. How can this be explained in...
Write dt/ds with constant H in terms of T,P,V.
Write dt/ds with constant H in terms of T,P,V.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT