Consider the following parts of spectra:
(1) Visible (2) Infrared (3) Ultraviolet (4) Microwave
Which of the following is the correct sequence in which the wavelengths increase?
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What is a mixture of potassium nitrate powdered charcoal and sulphur called?
How many nodes does a 4d orbital possess?
After 280 days, the activity of a radioactive sample is 6000 dps. The activity reduces to 3000 dps after another 140 days. The initial activity of the sample in dps is:
One of the essential minerals in the human body is salt. How much salt (NaCl) is in the average adult human body?
Which of the following elements behave chemically both as a metal and a non metal?
Alkanes are ____________.
When soggy biscuits are kept inside the fridge for sometime they become crisp because:
The gas used in the manufacture of vanaspati from vegetable oil is:
The molecular formula of phosphorous is:
The number of geometric isomers that can exist for square planar [Pt (Cl) (py) (NH3) (NH2OH)]+ is (py = pyridine) :
Increasing order of stability among the three main conformations (i.e. Eclipse, Anti, Gauche) of 2-fluoroethanol is:
The main chemical constituent of clay is:
Higher order (>3) reactions are rare due to :
What do non metal atoms lose to form negatively charged ions?
The most electronegative element among the following is :
Consider the following statements regarding diamond:
(1) It is an allotrope of silicon.
(2) It is a bad conductor of heat and electricity.
(3) It is the hardest substance.
(4) It burns to produce carbon dioxide.
Which of the statements given above are correct?
The term anomers of glucose refers to:
The ESR spectrum of the quinoxaline anion features fine structure resulting from the coupling of the electron spin to the hydrogen nuclei. The observed coupling constants are shown below. Calculate the spin densities on each of the carbon atoms at the positions labelled.
Which of the following statements in relation to the hydrogen atom is correct?
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.
Toluene is nitrated and the resulting product is reduced with tin and hydrochloric acid. The product so obtained is diazotised and then heated with cuprous bromide. The reaction mixture so formed contains:
A catalyst is a substance which:
Elimination of bromine from 2-bromobutane results in the formation of-
The gas used for artificial ripening of green fruit is ?
Which of the vitamins given below is water soluble ?
Consider the following statements and select the correct code.
Assertion (A): The main constituent of the
liquefied petroleum gas is methane.
Reason (R): Methane can be used directly for burning in homes and factories where it can be supplied through pipelines.
The acid generally stored in batteries is:
What is the degeneracy of the energy level with n = 6 in a hydrogenic atom or ion?
Which of the following gases is the most toxic?