The names of the scientists, Newlands, Mendeleev, and Meyer are associated with the development of:
The hardest form of carbon is:
The following are the half lives of four active isotopes. Which one of the following is the most dangerous to handle?
Due to rusting the weight of iron:
A cylinder of volume 1810 dm3 contains gas at a pressure of 197 atm and temperature of 25°C. Assuming that the gas behaves as a perfect gas, calculate the amount of gas contained in the cylinder.
The compound that has the least value for octane number is :
What is the degeneracy of the rotational energy level with J = 4 for a heteronuclear diatomic molecule?
What is hottest part of the gas flame is called ?
If you fill a glass to the brim with ice water and the ice melts, what will happen?
The law which states that the amount of gas dissolved in a liquid is proportional to its partial pressure is:
Acid rains is caused due to emission of which of the following into the atmosphere?
Which of the following do not contain nitrogen element?
(1) Superphosphate of lime
(2) Urea (3) Indian saltpeter
(4) Chille saltpeter
Which one of the following types of drugs reduces fever?
Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives:
Which one is an organic Acid ?
Which one among the following elements/ions is essential in small quantities for development of healthy teeth but causes mottling of the teeth if consumed in higher quantities?
The pH of water at 25°C is 7. When it is heated to 100°C, the pH of water:
The lowest energy level fills with ____________ first.
Alloys made with mercury as one metal are called ?
The gas used for artificial ripening of green fruit is ?
Consider the following statements:
(1) A molecule of sulphur contains 4 sulphur atoms.
(2) Metals placed below hydrogen in activity series lose electrons to H+ ions of acids.
(3) Silver acquires a blackish tinge when exposed to air for a long time.
Which of these statement(s) is/are correct ?
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.
Assertion : Nitrogen and Oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen.
Reason : The reaction between nitrogen and oxygen requires high temperature.
The Pauling electronegativities of fluorine and chlorine are 4.0 and 3.0 respectively. Estimate the dipole moment of chlorine monofluoride, ClF.
Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are given. Which of these statements gives the correct picture?
Hydrofluoric acid is not kept in glass bottles because it reacts with:
Which of the following compounds is not an antacid?
The main use of salt in the diet is to:
Which one of the following statements is not true about the effect of an increase in temperature on the distribution of molecular speeds in a gas?
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.