NTA JEE Main 25th July 2021 Shift 1

Consider the complete combustion of butane, the amount of butane utilized to produce 72.0 g of water is ___ $$\times 10^{-1}$$ g. (in nearest integer)

A source of monochromatic radiation wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, $$x \times 10^{20}$$ electrons are ejected per second. Assume that wavelength 400 nm is sufficient for ejection of electron from the surface of sodium metal. The value of x is ___. (Nearest integer)
h = 6.626 $$\times 10^{-34}$$ Js

A home owner uses $$4.00 \times 10^3$$ m$$^3$$ of methane CH$$_4$$ gas, (assume CH$$_4$$ is an ideal gas) in a year to heat his home. Under the pressure of 1.0 atm and 300 K, mass of gas used is $$x \times 10^5$$ g. The value of x is ___.
(Nearest integer)
(Given R = 0.083 L atm K$$^{-1}$$ mol$$^{-1}$$)

At 298 K, the enthalpy of fusion of a solid X is 2.8 kJ mol$$^{-1}$$ and the enthalpy of vaporisation of the liquid X is 98.2 kJ mol$$^{-1}$$. The enthalpy of sublimation of the substance X in kJ mol$$^{-1}$$ is ___. (in nearest integer)

For the reaction
A + B $$\rightleftharpoons$$ 2C
the value of equilibrium constant is 100 at 298 K. If the initial concentration of all the three species is 1 M each, then the equilibrium concentration of C is $$x \times 10^{-1}$$ M. The value of x is ___. (Nearest integer)

When 10 mL of an aqueous solution of Fe$$^{2+}$$ ions was titrated in the presence of dil H$$_2$$SO$$_4$$ using diphenylamine indicator, 15 mL of 0.02 M solution of K$$_2$$Cr$$_2$$O$$_7$$ was required to get the end point. The molarity of the solution containing Fe$$^{2+}$$ ions is $$x \times 10^{-2}$$ M. The value of x is ___. (Nearest integer)

The number of sigma bonds in the above molecule is ___.

CO$$_2$$ gas is bubbled through water during a soft drink manufacturing process at 298 K. If CO$$_2$$ exerts a partial pressure of 0.835 bar then x m mol of CO$$_2$$ would dissolve in 0.9 L of water. The value of x is ___.
(Nearest integer)
(Henry's law constant for CO$$_2$$ at 298 K is $$1.67 \times 10^3$$ bar)

Consider the cell at 25$$^\circ$$C
Zn|Zn$$^{2+}$$ aq, 1 M || Fe$$^{3+}$$(aq), Fe$$^{2+}$$aq|Pt
The fraction of total iron present as Fe$$^{3+}$$ ion at the cell potential of 1.500 V is $$x \times 10^{-2}$$. The value of x is ___.
(Nearest integer)
Given: E$$^\circ_{Fe^{3+}|Fe^{2+}}$$ = 0.77V, E$$^\circ_{Zn^{2+}|Zn}$$ = -0.76V

Three moles of AgCl get precipitated when one mole of an octahedral co-ordination compound with empirical formula CrCl$$_3$$.3NH$$_3$$.3H$$_2$$O reacts with excess of silver nitrate. The number of chloride ions satisfying the secondary valency of the metal ion is ___.