question_answer2) The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to high concentration of :-
[JEE Main Solved Paper-2016 ]
question_answer5) Two closed bulbs of equal volume(V) containing an ideal gas initially at pressure \[{{p}_{i}}\] and temperature \[{{T}_{1}}\]are connected through a narrow tube of negligible volume as shown in the figure below. The temperature of one of the bulbs is then raised to \[{{T}_{2}}\]The final pressure \[{{p}_{f}}\] is :-
[JEE Main Solved Paper-2016 ]
question_answer6) The heats of combustion of carbon and carbon monoxide are -393.5 and -285.5 kJ \[\text{mo}{{\text{l}}^{\text{-1}}},\] respectively. The heat of formation (in kJ) of carbon monoxide per mole is :-
[JEE Main Solved Paper-2016 ]
question_answer7) At 300 K and 1 atm, 15 mL of a gaseous hydrocarbon requires 375 mL air containing 20% \[{{O}_{2}}\] by volume for complete combustion. After combustion the gases occupy 330 mL. Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure, the formula of the hydrocarbon is :-
[JEE Main Solved Paper-2016 ]
question_answer8) Decomposition of \[{{H}_{2}}{{O}_{2}}\]follows a first order reaction. In fifty minutes the concentration of \[{{H}_{2}}{{O}_{2}}\]decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of \[{{H}_{2}}{{O}_{2}}\]reaches 0.05 M, the rate of formation of \[{{O}_{2}}\]will be :-
[JEE Main Solved Paper-2016 ]
question_answer9) The pair having the same magnetic moment is:- \[[\text{At}.\text{No}.:\text{Cr}=\text{24},\text{Mn}=\text{25},\text{Fe}=\text{26},\text{Co}=\text{27}]\]
[JEE Main Solved Paper-2016 ]
question_answer13) The distillation technique most suited for separating glycerol from spent-lye in the soap industry is :
[JEE Main Solved Paper-2016 ]
question_answer16) In the Hofmann bromamide degradation reaction, the number of moles of NaOH and \[\text{B}{{\text{r}}_{\text{2}}}\]used per mole of amine produced are :
[JEE Main Solved Paper-2016 ]
A)
Four moles of NaOH and one mole of \[\text{B}{{\text{r}}_{\text{2}}}\]
doneclear
B)
One mole of NaOH and one mole of \[\text{B}{{\text{r}}_{\text{2}}}\]
doneclear
C)
Four moles of NaOH and two moles of \[\text{B}{{\text{r}}_{\text{2}}}\]
doneclear
D)
Two moles of NaOH and two moles of \[\text{B}{{\text{r}}_{\text{2}}}\]
question_answer20) A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If e and m are charge and mass of an electron respectively, then the value of\[h/\lambda \](where \[\lambda \]is wavelength associated with electron wave) is given by :
[JEE Main Solved Paper-2016 ]
question_answer21) 18 g glucose \[({{C}_{6}}{{H}_{12}}{{O}_{6}})\]is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is :
[JEE Main Solved Paper-2016 ]
question_answer27) For a linear plot of log(x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct ? (k and n are constants)
[JEE Main Solved Paper-2016 ]
question_answer29) The equilibrium constants at 298 K for a reaction \[A+BC+D\]is 100. If the initial concentration of all the four species were 1 M each, then equilibrium concentration of D (in mol\[{{L}^{-1}}\]) will be :
[JEE Main Solved Paper-2016 ]