What is laughing gas ?
What is used to avoid melting of ice ?
The pH of water at 25°C is 7. When it is heated to 100°C, the pH of water:
Decreases up to 50°C and then increases
Who is regarded as father of modern chemistry ?
Which among the following is the objective of the Methyl tert-butyl ether (MTBE) mixing with Petroleum?
Raise Octane Number
How many nodes does a 4d orbital possess?
3, of which 1 is an angular node and 2 are radial nodes
3, of which 2 are angular nodes and 1 a radial node
3, of which all are radial nodes
3, of which all are angular nodes
The mass number of a nucleus is:
Always less than its atomic number
The sum of the number of protons and neutrons present in the nucleus
Always more than the atomic weight
Due to rusting the weight of iron:
Remains the same
The number of moles of solute present in 1 kg of a solvent is called its:
DNA codes for proteins, which are the building blocks of organisms. What is the most abundant protein in the human body?
The ore which is found in abundance in India is ?
In which among the following categories, Radon (Rn) can be placed? (1) Radioactive Element (2) Inert Gas (3) Noble Gas Choose the correct option:
1 & 2
2 & 3
1, 2 & 3
Why ethylene dibromide is added to petrol - (1) It increases the octane number of fuel (2) It helps in elimination of lead oxide (3) It removes the sulphur compound in petrol (4) It serves as a substitute of tetraethyl lead:
1 and 2
2 and 3
Which of the statements given below is/are correct? Permanent hardness of water is due to the presence of soluble. (1) Chloride of calcium (2) Bicarbonate of calcium (3) Sulphate of magnesium (4) Bicarbonate of magnesium Select the correct answer using the codes given below.
1 and 3 only
2 and 4
1, 2 and 3
How many different oxides are formed by nitrogen ?
The Pauling electronegativities of fluorine and chlorine are 4.0 and 3.0 respectively. Estimate the dipole moment of chlorine monofluoride, ClF.
Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution. What is the molarity of the final mixture?
The high reactivity of fluorine is due to ?
Small size of fluorine atom
Its high electro negativity
Availability of d-orbitals
Strong F - F bond
The quantum yield for the quenching of an excited fluorescing state was measured to be 0.34 with a lifetime of 4.1 ns. Calculate the lifetime of the state in the absence of a quencher.
Group 0 elements are ____________.
Unreactive non metals
Reactive non metals
What are reactive metals called?
Among the following acids which has the lowest pKa value?
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:
Increase by a factor of 4
The most electronegative element among the following is :
Hydrofluoric acid is not kept in glass bottles because it reacts with:
Sodium oxide of glass
Aluminium oxide of glass
Silicon dioxide of glass
Which one among the following statements regarding the properties of mixtures and compounds is not correct?
A mixture shows the properties of its constituents but the properties of a compound are entirely different from its constituents
A mixture may be homogeneous or heterogeneous but a compound is a homogeneous substance
The constituents of a mixture can be separated by physical methods but those of a compound cannot be separated by physical methods
Energy is either absorbed or evolved during the preparation of a mixture but not in the preparation of a compound
Amount of oxalic acid present in a solution can be determined by its titration with KMnO4 solution in the presence of H2SO4. The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl:
Gets oxidised by oxalic acid to chlorine
Furnishes H+ ions in addition to those from oxalic acid
Reduces permanganate to Mn2+
Oxidises oxalic acid to carbon dioxide and water
The molecule which has the highest percentage of ionic character among the following is:
White Phosphorous is represented by which among the following symbols?
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