NEET UG 2019 — Physical Chemistry

A first order reaction has a rate constant of $2.303 \times 10^{-3} \mathrm{~s}^{-1}$. The time required for $40 \mathrm{~g}$ of this reactant to reduce to $10 \mathrm{~g}$ will be [Given that $\log _{10} 2=0.3010$ ]

An ideal gas expands isothermally from $10^{-3} \mathrm{~m}^3$ to $10^{-2} \mathrm{~m}^3$ at $300 \mathrm{~K}$ against a constant pressure of $10^5 \mathrm{Nm}^{-2}$. The work done on the gas is

$4d, 5p, 5f$ and $6p$ orbitals are arranged in the order of decreasing energy. The correct option is:

Conjugate base for Bronsted acids ${\text{H}}_{2} \text{O}$ and $\text{HF}$ are:

Following limiting molar conductivities are given as given as $$ \begin{aligned} & \lambda_{\mathrm{m}\left(\mathrm{H}_2 \mathrm{SO}_4\right)}^0=\mathrm{x} \mathrm{S} \mathrm{cm}{ }^2 \mathrm{~mol}^{-1} \\ & \lambda_{\mathrm{m}\left(\mathrm{K}_2 \mathrm{SO}_4\right)}^0=\mathrm{y} \mathrm{S} \mathrm{cm}{ }^2 \mathrm{~mol}^{-1} \\ & \end{aligned} $$ $\lambda_{\mathrm{m}\left(\mathrm{CH}_2 \mathrm{COOK}\right)}^0=\mathrm{Z} \mathrm{S} \mathrm{cm}{ }^2 \mathrm{~mol}^{-1}$

For a cell involving one electron ${E}_{cell}^{\circleddash }=0.59 V$ at $298 K$, the equilibrium constant for the cell reaction is: $[Given that \frac{2.303 RT}{F}=0.059 V at T=298 K]$

For a reaction, activation energy $\mathrm{E}_{\mathrm{a}}=0$ and the rate constant at $200 \mathrm{~K}$ is $1.6 \times 10^6 \mathrm{~s}^{-1}$. The rate constant at $400 \mathrm{~K}$ will be [Given that gas constant $\mathrm{R}=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$ ]

For an ideal solution, the correct option is:

For the cell reaction $2F{e}^{3+}(aq)+2{I}^{-}(aq)\rightarrow 2F{e}^{2+}(aq)+{I}_{2}(aq)$ ${E}_{cell}^{0}=0.24 V$ at $298 K.$ The standard Gibbs energy $({\Delta }_{r}{G}^{-})$ of the cell reaction is: [Given that Faraday constant $F=96500 Cmo{l}^{-1}$ ]

For the chemical reaction ${N}_{2}(g)+3{H}_{2}(g)\rightleftharpoons 2N{H}_{3}(g)$, the correct option is:

If the rate constant for a first order reaction is $k$, the time $(t)$ required for the completion of $99%$ of the reaction is given by

In hydrogen atom, the de-Broglie wavelength of an electron in the second Bohr orbit is [Given that, Bohr radius, $\mathrm{a}_0=52.9 \mathrm{pm}$ ]

In water saturated air the mole fraction of water vapour is 0.02 . If the total pressure of the saturated air is $1.2 \mathrm{~atm}$, the partial pressure of dry air is

In which case change in entropy is negative?

Orbital having 3 angular nodes and 3 total nodes is

pH of a saturated solution of $Ca{(OH)}_{2}$ is $9$ . The solubility product $({K}_{sp})$ of $Ca{(OH)}_{2}$ is:

Reversible expansion of an ideal gas under isothermal and adiabatic conditions are as shown in the figure.  $A B \rightarrow$ Isothermal expansion $A C \rightarrow$ Adiabatic expansion Which of the following option is not correct?

The density of $2 \mathrm{M}$ aqueous solution of $\mathrm{NaOH}$ is $1.28 \mathrm{~g} / \mathrm{cm}^3$. The molality of the solution is [Given that molecular mass of $\left.\mathrm{NaOH}=40 \mathrm{~g} \mathrm{~mol}^{-1}\right]$

The mixture that forms maximum boiling azeotrope is

The molar solubility of $\mathrm{CaF}_2$ $\left(\mathrm{K}_{\mathrm{sp}}=5.3 \times 10^{-11}\right)$ in $0.1 \mathrm{M}$ solution of $\mathrm{NaF}$ will be

The $\mathrm{pH}$ of $0.01 \mathrm{M} \mathrm{NaOH}(a q)$ solution will be

The oxidation state of $\mathrm{Cr}$ in $\mathrm{CrO}_5$ is

The standard electrode potential $\left(\mathrm{E}^{-}\right)$values of $\left(\mathrm{Al}^{3+} / \mathrm{Al}, \mathrm{Ag}^{+} / \mathrm{Ag}, \mathrm{K}^{+} / \mathrm{K}\right.$ and $\mathrm{Cr}^{3+} / \mathrm{Cr}$ are $-1.66 \mathrm{~V}, 0.80 \mathrm{~V}, 2.93 \mathrm{~V}$ and $-0.74 \mathrm{~V}$, respectively. The correct decreasing order of reducing power of the metal is

Under the isothermal condition, a gas at $300 K$ expands from $0.1 L$ to $0.25 L$ against a constant external pressure of $2$ bar. The work done by the gas is (Given that $1 L$ bar$=100 J$)

Which of the following cannot act both as Bronsted acid and as Bronsted base?

Which of the following reactions are disproportionation reaction? $(a)$ $2C{u}^{+}\rightarrow C{u}^{2+}+C{u}^{0}$ $(b)$ $3Mn{O}_{4}^{2-}+4{H}^{+}\rightarrow 2Mn{O}_{4}^{-}+Mn{O}_{2}+2{H}_{2}O$ $(c)$ $2KMn{O}_{4}\overset{\Delta }{\rightarrow }{K}_{2}Mn{O}_{4}+Mn{O}_{2}+{O}_{2}$ $(d)$ $2Mn{O}_{4}^{-}+3M{n}^{2+}+2{H}_{2}O\rightarrow 5Mn{O}_{2}+4{H}^{\oplus }$ Select the correct option from the following:

Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region?

Which of the following statements is correct regarding a solution of two compounds A and $\mathrm{B}$ exhibiting positive deviation from ideal behaviour?

Which will make basic buffer?