Pytania i odpowiedzi
kocham pwr
Zebrane pytania i odpowiedzi do zestawu.
Ilość pytań: 41
Rozwiązywany: 1118 razy
Pytanie 21
The rate of reaction 2A+B->3C is equal to
-d[B]/dt
-1/2d[A]/dt
1⁄3 d[C]/dt
Pytanie 22
In first- order reaction
The half-life does not depend on concentration of the reaction
Pytanie 23
In a catalysed reaction
The catalyst is not consumed
The catalyst changes the reaction path
The catalyst changes the activation energy
Pytanie 24
For a perfect gas:
pV is proportional to absolute temperature
the enthalpy does not depend on pressure
Cv= Cp-nR
Molar entropy does not depend on pressure
Molar entropy always increases with temperature
The internal energy depends on temperature only
Pytanie 25
In a reversible adiabatic process
ΔU=w
Pytanie 26
. The standard enthalpy of combustion of a compound:
is defined at standard pressure
is the heat effect of reaction of combustion of 1 mole of a compound in air at standard pressure
is equal to TΔCSO +ΔCGO
Pytanie 27
The entropy change in an isothermal decompression of a perfect gas against constant pressure
is equal to Δ(pV)/T
Pytanie 28
In first order phase transition:
The heat capacity shows a discontinuity
Entropy shows a discontinuity
thermal expresion coefficient shows a discontinuity
Pytanie 29
The chemical potential μi
at the triple point of a substance is equal for solid, liquid and vapor
is always equal to μ_i= μ_i^°+RTln(a_i)
Always decreases with temperature rise
is equal to μ_i= μ_i^°+Rln(p_i/p^0 ) but only for perfect gas mixtures
Has a minimum at the triple point
Pytanie 30
The entropy of mixing:
is equal to -Rlnx in system (raoult's law)
is 0 for perfect gases
Pytanie 31
For the concentration cell Ag|Ag+(c1)||Ag+(c2)|Ag
emf is positive if c2>c1
ΔrSO > 0 for c2>c1
Pytanie 32
In reactions A+B---(k1)--->C 2C---(k2)--->D k2>>k1 Therefore:
the steady-state approx. can be used for [C]
the steady-state approx. cannot be used for [B]
d[D]/dt ≈((k1 k2)/(k1+k2 ))* [A][B]
Pytanie 33
. In reactions A+B---(k1)--->C---(k2)--->D---(k3)--->E k3>> k1>>k2 Therefore:
the steady-state approx. can be used for [C]
the steady-state approx. can be used for [D]
[D]≈k_2/k_3 [C]
d[C]/dt ≈k_1 * [A][B]
Pytanie 34
In an isotherml expansion
ΔH=0 only for prefect gas
Pytanie 35
. The standard enthalpy of formation of a compound:
is zero for graphite
is zero for graphene
is equal to TΔfSO +ΔfGO
Pytanie 36
The entropy change in an adiabatic decompression of a perfect gas against constant pressure
is equal to zero
Pytanie 37
The boiling point of a substance:
increases with pressure for all substances
Must be lower than the critical point temperature
Must be higher than the triple point temperature
Pytanie 38
Limiting molar conductivity of sodium acetate:
can be determined from A=f(c^0,5 ) dependence
can be determined from inverse conductance vs inverse concentration plot
Pytanie 39
In zeroth-order reaction A = products
reaction rate constant does not depend on concentration of the reactant
reaction rate does not depend on time
Pytanie 40
For enzyme-catalysed reaction
the reaction rate is proportional to [ES]
Pytanie 41
The viscosity
relates the rate of momentum transfer to the velocity gradient