Argon is used
in filling airships
to obtain low temperature
in high temperature welding
in radiotherapy for treatment of cancer
The number of electrons, neutrons and protons in a species are equal to 10, 8 and 8 respectively. The proper symbol of the species is
56 g of nitrogen and 96 g of oxygen are mixed isothermally and at a total pressure of 10 atrn. The partial pressures of oxygen and nitrogen (in atm) are respectively
4, 6
5, 5
2, 8
6, 4
According to the first law of thermodynamics which of the following quantities represents the change in a state function?
qrev
qrev - Wrev
qrev + Wrev
The expression for the solubility product of Ag2CO3 will be
Ksp = s2
Ksp = 4s3
Ksp = 27s4
Ksp = s
A 600 W mercury lamp emits monochromatic radiation of wavelength 331.3 nm. How many photons are emitted from the lamp per second? (h = 6.626x 10-34 J-s; velocity of light = 3x108 ms-1)
1 x 1019
1 x 1020
1 x 1021
1 x 1023
Which of the following fluorides does not exist?
NF5
PF5
AsF5
SbF5
A.
NF5
P, As and Sb form pentahalides of the general formula EX5 (where, E = P, As and Sb) due to the presence of vacant d-orbitals in their respective valence shell. N does not form pentahalides due to the absence of d-orbitals in its valence shell.