The IUPAC name for the complex [Co(NO2)(NH3)5]Cl2 is:
Atomic number is equal to :
Bleaching action of chlorine is by ?
Chlorophyll molecules act as both donors and acceptors in fluorescence resonance energy transfer. The fluorescence lifetime of chlorophyll molecules in a dilute solution of an organic solvent wa found to be 1.2 ns. When chlorophyll molecules were instead embedded in a biopolymer, the fluorescence lifetime was measured to be 820 ps. Given that R0 = 5.6 nm for chlorophyll molecules, estimate the separation between the donor-acceptor pairs in the polymer.
What is atomic number of an atom?
Which of the following statements about diamond are correct?
(1) It is used as a gem in jewellery because of its ability to reflect light.
(2) It is good conductor of electricity.
(3) It is used for cutting glass, marble stones and other hard materials.
(4) It is used for drilling of rocks.
Select the correct answer using the codes given below :
The first metal used by man was:
Phenyl magnesium bromide reacts with methanol to give:
In Periodic table vertical columns are called ____________.
The oxidation state of chromium in the final product formed by the reaction between KI and acidified potassium dichromate solution is:
The synthesis of alkyl fluorides is best accomplished by :
To which orbitals may an electron in a 2p orbital in a hydrogenic atom make allowed spectroscopic transitions?
The standard Gibbs energy change at 300 K for the reaction 2A B + C is 2494.2 J. At a given time, the composition of the reaction mixture is [A] = 1/2, [B] = 2 and [C] = 1/2. The reaction proceeds in the :[R = 8.314 J/K/mol, e = 2.718]:
Which gas is filled in refrigerators ?
Which of the following statements is true for an ideal-dilute solution?
Which of the following pairs are correctly matched?
(1) Isotopes : Atoms with same atomic number but different atomic mass.
(2) Isobars : Atoms with same number of neutrons but different atomic number.
(3) Isotones : Atoms with same mass number but different atomic number.
Select the correct answer using the codes given below :
The method that cannot be used for removing permanent hardness of water is:
The metal does not give H2 on treatment with dilute HCL is:
Among the following substituted silanes the one which will give rise to cross linked silicone polymer on hydrolysis is:
Until the nineteenth Century, aluminium was almost as expensive as gold. The invention of an inexpensive way to extract this metal by a 22-year-old American made this metal inexpensive subsequently. The inventor was:
The most electropositive elements among the following is :
A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of carbon monoxide is doubled, with everything else kept the same, the rate of reaction will:
The oldest rocks in the earth's crust were once molten, and came from deep inside the earth. The molten rock, called magma, spewed out in volcanic eruptions during the earth;s early life and solidified into hard rock's called:
Which among the following oxides cause the Acid rain ?
The root-mean-square distance between the ends of a polymer chain was found to be 6.2 nm. Estimate the number of monomers in the chain, given that the length of each monomer unit is 2.1 Å.
Which of the following compounds is not an antacid?
Consider the following statements : The purpose of adding sodium sulphate and sodium silicate to washing powder is -
(1) To keep washing powder dry
(2) To maintain the alkalinity of the powder which of these statements is/are correct ?