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20 g of an ideal gas contains only atoms of S and O occupies 5.6 L at NPT. What is the mol. wt. of gas ?
Mass of gas = 20 g
Pressure of gas = 1 atm
Volume of gas = 5.6 L
Temperature of gas = 273 K
Using ideal gas law,
P = pressure of the gas
V = volume of the gas
T = temperature of the gas
n = number of moles of the gas
R = gas constant = 0.0821
M = molar mass of gas
w = mass of gas
Now put all the given values in the formula, we get
Therefore, the molar mass of the gas is, 80.0475 g/mole
5.6 litres of a gas at N.T.P. are found to have a mass of 11 g. The molecular mass of the gas is
A crystalline salt Na2SO4.xH2O on heating losses 55.9 per cent of its mass. The formula of crystalline salt is---
Vapour density of a metal chloride is 66. Its oxide contains 53% metal. The atomic weight of the metal is
When two aqueous solutions react together to give off solid product, this reaction is known as
At S.T.P. the density of CCl4 vapour in g/L will be nearest to
Which of the following transitions of electrons in the hydrogen, atom will emit maximum energy ?
The uncertainty found from the uncertainty principle (Δx.Δp = h/4 π) is
The number of atoms of hydrogen in 2 moles of NH3
Therefore 2 moles will have 1.204*1024 molecules of NH3.
There are 4 atoms in each molecule, so 2 moles will have 4*(1.204*1024) atoms
which is 4.816*1024 atoms.
The spectrum of He is expected to be similar to that of
The spectrum of an atom depends on the number of electrons present in it. Here, helium has two electrons, so the spectrum of Li+ (Z = 3) is similar to that of helium because both He and Li+ have two electrons.
The electrons present in K-shell of the atom will differ in
Which of the following statements about quantum numbers is wrong?
If the value of l=0, then electron lies in s-subshell which has spherical shape. So electron distribution is spherical.
Shape of orbital is given by azimuthal quantum number as it describes the subshell.
Magnetic quantum number determines the shift of atomic orbital due to external magnetic field i.e., zeeman effect.
Spin quantum number describes the spin of electron in particular orbital. Orientations of electron cloud is specified of a magnetic quantum number.
So B option is incorrect.
Out of the two compounds shown below, the vapour pressing of B at a particular temperature is expected to be
Because of intramolecular hydrogen bonding in (B), i.e., ortho nitrophenol, the vapour pressure of ortho nitrophenol is expected to be higher than paranitrophenol.
Therefore, the correct option is A.
In which of the following molecules, the central atom does not use sP3-hybrid orbitals in its bonding ?
In the given options, BeF3−, Be forms three sigma bonds with three flourines.
So, hybridisation of Be becomes sp2.
Hence, the correct answer is option A.
The correct increasing bond angle among , and
BF3is trigonal planar which makes the angle as 120 degree.PF3 is trigonal bipyramidal making the angle slightly less than 109 degrees ClF3 is T-shaped making the least angle.
The ionic species having largest size is
Li+ ion being smallest in size is heavily hydrated and thus Li+(aq) is largest in size.
From which of the following species it is easiest to remove one electron ?
Energy is released when an electron is added to the atom. Hence 1st electron affinity (EA1) is always taken as negative. The addition of second electron to the negativity charged ions is opposed by Coulombic repulsion, hence energy has to be supplied for the addition of second electron. Hence (EA2) is taken as positive.
Addition of an electron to F− and O− ions will involve repulsions, hence their (EA2) will be positive.
Due to stable fully filled configuration of Na+ (1s2 2s2 2p6) it has lower value of electron affinity than O. Hence O has highest electron affinity.
Which element has the greatest tendency to lose electrons ?
0.01 mole of iodoform (CHI3) reacts with Ag to produce a gas whose volume at NTP in ml is :-
2CHI3 + 6Ag —→ 6AgI(s) + C2H2(g)
mol of C2H2 = 1/2 × mol of CHI3
= 1/2 × 0.01 = 0.005
volume at N.T.P. = 0.005 × 22400 = 112 ml
Sum of σ and π bonds are present in CH3COOH?
Single bond is σ bond and double bond contains 1σ and 1 π bond. Therefore, it contains 7 σ and 1 π bond. Hence, total is 8
How many maximum electrons can be accomodate in 7th shell of element X?
Maximum number of electron in a shell
How many groups show – I effect?
Number of lone pair present in P4O6.