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Δ U is equal to
Isochoric work
Isobaric work
Adiabatic work
Isothermal work
C.
Adiabatic work
From 1st law thermodynamics:
ΔU = q + w
For adiabatic process :
q = 0
∴ ΔU = w
∴ Work involves in the adiabatic process is at the expense of a change in internal energy of the system.
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The radius of the second Bohr orbit for the hydrogen atom is :
(Plank's const. h = 6.6262 × 10–34 Js ; mass of electron = 9.1091 × 10–31 kg ; charge of electron
e = 1.60210 × 10–19 C ; permittivity of vacuum
∈0 = 8.854185 × 10–12 kg–1 m–3 A2)
1.65Å
4.76Å
0.529Å
2.12Å
D.
2.12Å
Radius of nth Bohr orbit in H-atom = 0.53 n2Å
Radius of II Bohr orbit = 0.53 ×(2)2 = 2.12 Å
pKa of a weak acid (HA) and pKb of a weak base (BOH) are 3.2 and 3.4, respectively. The pH of their salt (AB) solution is
7.2
6.9
7.0
1.0
B.
6.9
Given
pKa (HA) = 3.2
pKb (BOH) = 3.4
As given salt is of weak acid and weak base
therefore,
pH = 7 + (1/2)pKa - (1/2)pKb
= 7 + (1/2)(3.2) - (1/2)(3.4)
= 6.9
The most abundant element by mass in the body of a healthy human adult are :
Oxygen (61.4%) ; Carbon (22.9%), Hydrogen(10.0%) ; and Nitrogen (2.6%). The weight which a 75 kg person would gain if all 1H atoms are replaced by 2H atoms is
15 kg
37.5 Kg
7.5 Kg
40 Kg
C.
7.5 Kg
Mass in the body of a healthy human adult has :-
Oxygen = 61.4%, Carbon = 22.9%,
Hydrogen = 10.0% and Nitrogen = 2.6%
Total weight of person = 75 kg
Mass due to 1H is =
(10/100)x 75 = 7.5kg
1H atoms are replaced by 2H atoms.
So mass gain by person =7.5 kg
In the following reactions, ZnO is respectively acting as a/an :
(a) ZnO + Na2O → Na2ZnO2
(b) ZnO + CO2 → ZnCO3
base and acid
base and base
acid and acid
acid and base
D.
acid and base
ZnO is amphoteric oxide,in given reaction,
(a) ZnO + Na2O → Na2ZnO2
In this reaction ZnO act as Acid.
(b) ZnO + CO2 → ZnCO3
In this reaction ZnO act as Base.
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Mock Test Series
