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?
The disperse phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged, respectively, which of the following statements is NOT correct?
2,4-D, which is sold as a weed killer of the broad-leaved weeds is a synthetic version of ____________:
Consider the following statements: Hard water is not suitable for
(1) Drinking
(2) Washing clothes with soap
(3) Use in boilers
(4) Irrigating crops
Which of these statements are correct?
The isotope atoms differ in ?
What is the general formula of Alkanes?
Which one of the following statements is not true about cosmic rays?
Imagine an atom made p of proton and a hypothetical particle of double the mass of the electron but having he same charge as the electron. Apply the Bohratom model and consider all posible transitions of this hypothetical particle to the first excited level. The longest waveength photon that will be emitted has wavelength λ (given in terms of the Rydberg constant R for the hydrogen atom) equal to:
Homo nuclear molecules contain ?
Which among the following element is an essential constituent of acids?
If elements with principal quantum number n> 4 were not allowed in nature, the number of possible elements would be:
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.
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.
The metal that is used as a catalyst in the hydrogenation of oils is:
Consider the following statements :
(1) Diamond is hard and graphite is soft.
(2) Diamond is soft and graphite is hard.
(3) Diamond is a bad conductor but graphite is a good conductor. (4) Diamond is a good conductor but graphite is a bad conductor.
Which of the statements given above is/are correct ?
An electron changes its position from n= 2 to the or bit n = 4 of an atom. The wave length of the emitted radiations is (R = Rydberg’s constant)
Three of the most common states of matter are solids, liquids, and gases. A liquid has:
Which of the following can be used for removal of stains of rust on clothes?
(1) H2O2 (2) Oxalic acid
(3) Petrol (4) Alcohol
In which of the following molecules/ions are all the bonds not equal?
How many normal modes of vibrational are possible for a benzene molecule?
Mass number of a nucleus is :
Polyunsaturated fats have ____________.
Which one of the following metals does not react with water to produce Hydrogen?
Which of the following substances is/are ozone depleting? Select the correct answer from the codes given below:
(1) Chlorofluorocarbons
(2) Halons
(3) Carbon tetrachloride
In Langmuir’s model of adsorption of a gas on a solid surface:
Which among the following is the objective of the Methyl tert-butyl ether (MTBE) mixing with Petroleum?
After any chemical reaction ____________.
Which of the following elements behave chemically both as a metal and a non metal?