If the binding energy of the electron in a hydrogen atom is 136 eV the energy required to remove the electron from the first excited state of Li++ is:
The major component used in preparation of different types of glasses is :
The names of the scientists, Newlands, Mendeleev, and Meyer are associated with the development of:
Periodic table of contents
Discovery of elements
When a tubelight breaks, a cracking sound is produced because ____________?
Pressure inside the lamp is less than atmospheric pressure
Pressure inside the lamp is more than atmospheric pressure
The lamp is filled with reactive gases
The lamp is filled with mercury vapour
The partial pressure of ethanol in the air above a sample of liquid ethanol is 10.5 Torr. Assuming the air to be at normal pressure, calculate the mole fraction of ethanol in the air.
The substance that contains the maximum amount of nitrogen is ?
The metal used to recover copper from a solution of copper sulphate is:
All noble gases are ?
Colourless and odourless
Colourless and but have odour
Acid rain is due to air pollution by ?
Nitrous oxide and Sulphur dioxide
Which among the following is popularly called Hypo?
Which one of the following types of drugs reduces fever?
The main chemical constituent of clay is:
Which of the following is/are the hazardous pollutant(s) present in automobile exhaust gases? (i) N2 (ii) CO (iii) CH4 (iv) Oxides of nitrogen
(ii) and (iii)
(i) and (ii)
(ii) and (iv)
(i) and (iii)
Consider the following statements: Assertion (A): LPG is a pollution free vehicular fuel. Reason (R): Plying of CNG fuelled-buses is recommended for metropolitan cities in India.
Both A and R are true, and R is the correct explanation of A
Both A and R are true, but R is not the correct explanation of A
A is true, but R is false
A is false, but R is true
Which among the following oxides cause the Acid rain ?
Carbon monoxide and carbon dioxide
Nitrous oxide and sulphur dioxide
Carbon dioxide and nitrous oxide
Sulphur dioxide and carbon monoxide
The heat energy produced when the human body metabolises 1 gram of fat is:
Unreactive non metals are called. ____________ .
The most commonly used bleaching agent is:
Which among the following is the objective of the Methyl tert-butyl ether (MTBE) mixing with Petroleum?
Raise Octane Number
Living in the atmosphere of CO is dangerous because it:
Reduces organic matter of tissues
Dries up the blood
Combined with O2 present inside to form CO2
Combines with haemoglobin and makes it incapable of absorbing oxygen
The vapour pressure of toluene is 6.811 kPa at 310 K and 24.15 kPa at 340 K. Assuming that the variation of the vapour pressure p with temperature T may be described by the expression What are the values of A and B?
A = 7.059, B = 1930 K
A = 5.307, B = 1930 K
A = 6.971, B = 7780 K
A = 5.307, B = 7780 K
Which of the following cannot be emitted by radioactive substances during their decay ?
The method of concentrating the ore which makes use of the difference in density between ore and impurities is called:
A radioactive sample at any instant has its disintegration rate of 5000 disintegrations per minute. After 5 minutes, the rate is 1250 disintegrations per minute. The decay constant per minute is:
0.8 ln 2
0.4 ln 2
0.2 ln 2
0.1 ln 2
What do metal atoms lose to form positively charged ions?
All of the above
Which of the following is correct?
Protons and Neutrons are electrically charged
Protons and Electrons are electrically charged
Electrons and Neutrons are electrically charged
Neutrons, Electrons and Protons are electrically charged
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 used to avoid melting of ice ?
Heating mixture of Cu2O and Cu2S will give:
Cu + SO2
Cu + SO3
CuO + CuS
The maximum number of covalent formed by nitrogen is:
Mark For Review & Next
© Copyright © 2020-2021 MyPariksha.com All Rights Reserved.