Chemistry Physical Chemistry questions from NEET UG 2013.
A button cell used in watches functions as following $\mathrm{Zn}(s)+\mathrm{Ag}_2 \mathrm{O}(s) & +\mathrm{H}_2 \mathrm{O}(l) \rightleftharpoons 2 \mathrm{Ag}(s) + \mathrm{Zn}^{2+}(\alpha q)+2 \mathrm{OH}^{-}(\alpha q)$ If half cell potentials are $\begin{aligned} \mathrm{Zn}^{2+}(a q)+2 e^{-} & \rightarrow \mathrm{Zn}(s) ; E^{\circ}=-0.76 \mathrm{~V} \\ \mathrm{Ag}_2 \mathrm{O}(s)+\mathrm{H}_2 \mathrm{O}(l) & +2 e^{-} \\ & \rightarrow 2 \mathrm{Ag}(s)+2 \mathrm{OH}^{-}(a q), \\ & E^{\circ}=0.34 \mathrm{~V} \end{aligned}$ The cell potential will be
A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of $\mathrm{pH}=10$ and by passing hydrogen gas around the platinum wire at $1 \mathrm{~atm}$ pressure. The oxidation potential of electrode would be
A magnetic moment of $1.73 \mathrm{BM}$ will be shown by one among the following
A reaction having equal energies of activation for forward and reverse reactions has
A reaction is $50 \%$ complete in 2 hours and $75 \%$ complete in 4 hours. The order of reaction is:
According to law of photochemical equivalence the energy absorbed (in erg/ mole $)$ is given as $\left(h=6.62 \times 10^{-27}\right.$ ergs, $\mathrm{c}=3 \times 10^{10} \mathrm{~cm} \mathrm{~s}^{-1}, \mathrm{~N}_{\mathrm{A}}=6.02 \times 10^{-23}$ $\left.\mathrm{mol}^{-1}\right)$ :
Accumulation of lactic acid $\left(\mathrm{HC}_3 \mathrm{H}_5 \mathrm{O}_3\right)$, a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 $\mathrm{M}$ aqueous solution, lactic acid is $3.7 \%$ dissociates. The value of dissociation constant, $\mathrm{K}_a$, for this acid will be:
An excess of $\mathrm{AgNO}_3$ is added to $100 \mathrm{~mL}$ of a $0.01 \mathrm{M}$ solution of dichlorotetraaquachromium (III) chloride. The number of moles of AgCl precipitate would be
At $25^{\circ} \mathrm{C}$ molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is $9.54 \mathrm{ohm}^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ and at infinite dilution its molar conductance is $238 \mathrm{ohm}^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$. The degree of ionisation of ammonium hydroxide at the same concentration and temperature is
At $100^{\circ} \mathrm{C}$ the $\mathrm{K}_w$ of water is 55 times its value at $25^{\circ} \mathrm{C}$. What will be the $\mathrm{pH}$ of neutral solution? $(\log 55=1.74)$
Based on equation $E=-2.178 \times 10^{-18} \mathrm{~J}\left(\frac{Z^2}{n^2}\right)$ certain conclusions are written. Which of them is not correct?
Consider the half-cell reduction reaction: $$ \begin{aligned} & \mathrm{Mn}^{2+}+2 e^{-} \rightarrow \mathrm{Mn}, \mathrm{E}^{\mathrm{o}}=-1.18 \mathrm{~V} \\ & \mathrm{Mn}^{2+} \rightarrow \mathrm{Mn}^{3+}+e^{-}, \mathrm{E}^{\mathrm{o}}=1.51 \mathrm{~V} \end{aligned} $$ The $\mathrm{E}^{\circ}$ for the reaction $3 \mathrm{Mn}^{2+} \rightarrow \mathrm{Mn}^0$ $+2 \mathrm{Mn}^{3+}$, and possibility of the forward reaction are respectively
For a reaction between $A$ and $B$ the order with respect to $A$ is 2 and the other with respect to $B$ is 3 . The concentrations of both $\mathrm{A}$ and $\mathrm{B}$ are doubled, the rate will increase by a factor of:
How many gram of cobalt metal will be deposited when a solution of cobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (1 Faraday = $96,500 \mathrm{C}$; Atomic mass of $\mathrm{Co}=59 u$ )
How many grams of concentrated nitric acid solution should be used to prepare $250 \mathrm{~mL}$ of $2.0 \mathrm{M} \mathrm{HNO}_3$ ? The concentrated acid is $70 \% \mathrm{HNO}_3$.
In an experiment it is shown that $10 \mathrm{ml}$ of $0.05 \mathrm{M}$ solution of chloride required 10 $\mathrm{ml}$ of $0.1 \mathrm{M}$ solution of $\mathrm{AgNO}_3$, which of the following will be the formula of the chloride ( $\mathrm{X}$ stands for the symbol of the element other than chlorine)
Maximum deviation from ideal gas is expected from
$6.02 \times 10^{20}$ molecules of urea are present in $100 \mathrm{~mL}$ of its solution. The concentration of solution is
The dissociation constant of a weak acid is $1 \times 10^{-4}$. In order to prepare a buffer solution with a pH $=5$, the [Salt]/ [Acid] ratio should be:
The value of $\mathrm{K}_{s p}$ of $\mathrm{CaCO}_3$ and $\mathrm{CaC}_2 \mathrm{O}_4$ are $4.7 \times 10^{-9}$ and $1.3 \times 10^{-9}$ respectively at $25^{\circ} \mathrm{C}$. If the mixture of these two is washed with water, what is the concentration of $\mathrm{Ca}^{2+}$ ions in water?
The value of Planck's constant is $6.63 \times 10^{-34} \mathrm{Js}$. The speed of light is $3 \times 10^{17} \mathrm{nms}^{-1}$. Which value is closest to the wavelength in nanometer of a quantum of light with frequency of $6 \times 10^{15} \mathrm{~s}^{-1} ?$
Three thermochemical equation are given below: (i) $\underset{\mathrm{kJJ} \mathrm{mol}^{-1}}{\mathrm{C}_{\text {(graphite) }}}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(g)} \Delta \mathrm{H}^{\circ}=x$ (iii) $\mathrm{CO}_{(\mathrm{gJ})}+1 / 2 \mathrm{O}_{2(\mathrm{gk}} \rightarrow \mathrm{CO}_{2(\mathrm{~g}) i} \Delta \mathrm{H}^{\circ}=\mathrm{z}$ Based on the above equations, find out which of the relationship given below is correct.
What is the activation energy for a reaction if its rate doubles when the temperature is raised from $20^{\circ} \mathrm{C}$ to $35^{\circ} \mathrm{C} ?\left(R=8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\right)$
What is the maximum numbers of electrons that can be associated with the following set of quantum numbers? $n=3, l=1$ and $m=-1$
When 5 litres of a gas mixture of methane and propane is perfectly combusted at $0^{\circ} \mathrm{C}$ and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed. The amount of heat released from the combustion in kJ $\left(\triangle \mathrm{H}_{\text {eomb }}\left(\mathrm{CH}_4\right)\right.$ $=890 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta \mathrm{H}_{\text {comb }}\left(\mathrm{C}_3 \mathrm{H}_8\right)=2220 \mathrm{~kJ}$ $\left.\mathrm{mol}^{-1}\right)$
Which condition is not satisfied by an ideal solution?
Which is the strongest acid in the following?
Which of these is least likely to act as a Lewis base?