When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1. When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v2. If v2 = x v1, the value of x will be ________.
In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf’s of two cells respectively is 3 : 2, the difference in the balancing length of the potentiometer wire in above two cases will be _____ cm.
Which of the following sets of quantum numbers is not allowed?
Match List-I with List-II.
Choose the correct answer from the options given below :
The IUPAC nomenclature of an element with electronic configuration [Rn] 5f146d17s2 is
The compound(s) that is(are) removed as slag during the extraction of copper is(A)CaO,(B)FeO,(C)Al2O3,(D)ZnO,(E)NiOChoose the correct answer from the options given below :
The reaction of H2O2 with potassium permanganate in acidic medium leads to the formation of mainly
Choose the correct order of density of the alkali metals.
The geometry around boron in the product ‘B’ formed from the following reaction is
The interhalogen compound formed from the reaction of bromine with excess of fluorine is a :
The photochemical smog does not generally contain :
A compound’A’ on reaction with ‘X’ and ‘Y’ produces the same major product but differentby product’a’ and ‘b’. Oxidation of’a’ gives a substance produced by ants.
Which one of the following reactions does not represent correct combination of substrateand product under the given conditions?
Melamine polymer is formed by the condensation of :
During the denaturation of proteins, which of these structures will remain intact?
Drugs used to bind to receptors, inhibiting its natural function and blocking a message are called:
The enthalpy of combustion of propane, graphite and dihydrogen at 298 K are –2220.0 kJ mol–1, –393.5 kJ mol–1 and –285.8 kJ mol–1, respectively. The magnitude of enthalpy of formation of propane (C3H8) is _____ kJ mol–1. (Nearest integer)
The half-life for the decomposition of gaseous compound A is 240 s when the gaseous pressure was 500 torr initially. When the pressure was 250 torr, the half-life was found to be 4.0 min. The order of the reaction is ______. (Nearest integer)
Consider the following metal complexes:[Co(NH3)6]3+[CoCl(NH3)5]2+[Co(CN)6]3–[Co(NH3)5(H2O)]3+The spin-only magnetic moment value of the complex that absorbs light with shortest wavelength is _______ B.M. (Nearest integer)
Among Co3+, Ti2+, V2+ and Cr2+ ions, one if used as a reagent cannot liberate H2 from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is________ B.M. (Nearest integer)
