The density of a 3 M Sodium thiosulphate solution (Na2S2O3) is 1.25 g per ml. Calculate
(i) the percentage by weight of sodium thiosulphate,
(ii) the mole fraction of sodium thiosulphate and
(iii) the molalities of Na+ and $$S_2O_3^{-2}$$ ions
Answer
(A)
(i) 37.92, (ii) 0.065, (iii) 7.732m, 3.865m
5
3 g of a salt of molecular weight 30 is dissolved in 250 g of water. The molality if the solution is _____.
Answer
(D)
0.4 m
6
Complete and balance the following equation:
Zn + $$NO_3^- \to$$ Zn2+ + $$NH_4^+$$
Answer
(A)
4Zn + NO3- + 10H+ → 4Zn2+ + NH4+ + 3H2O
7
Linear overlap of two atomic p-orbitals leads to a sigma bond.
Answer
(A)
TRUE
8
An organic compound CxH2yOy was burnt with twice the amount of oxygen needed for complete combustion of CO2 and H2O. The hot gases when cooled to 0oC and 1 atm pressure, measured 2.24 litres. The water collected during cooling weighed 0.9 g. The vapour pressure of pure water at 20oC is 17.5 mm Hg and is lowered by 0.104 mm when 50 g of the organic compound are dissolved in 1000 g of water. Give the molecular formula of the organic compound.
Answer
(D)
C5H10O5
9
Heavy water is
Answer
(C)
D2O
10
The absorption of hydrogen by palladium is commonly known as ______.
Answer
(C)
Occlusion
11
Which one among the following does not have the hydrogen bond?
Answer
(D)
liquid HCl
12
The types of bonds present in CuSO4.5H2O are only
Answer
(C)
electrovalent, covalent and coordinate covalent
13
Carbon tetrachloride has no net dipole moment because of
Answer
(B)
its regular tetrahedral structure
14
Rutherford's scattering experiment is related to the size of the
Answer
(A)
nucleus
15
Any p-orbital can accommodate upto
Answer
(D)
two electrons with opposite spins
16
The principal quantum number of an atom is related to the
Answer
(A)
size of the orbital
17
The energy of the electron in the 3d-orbital is less than that in the 4s-orbital in the hydrogen atom.
Answer
(B)
FALSE
18
Gamma rays are electromagnetic radiations of wavelengths of 10-6 to 10-5 cm
Answer
(B)
FALSE
19
Elements of the same mass number but of different atomic numbers are known as ____.
