NTA JEE Main 2025 April 4th Shift 2

Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of 2 g mL$$^{-1}$$. The concentration of dissolved oxygen (O$$_2$$) in sea water is 5.8 ppm. Then the concentration of dissolved oxygen (O$$_2$$) in sea water, is $$x \times 10^{-4}$$ m. (Nearest integer)
Given: Molar mass of $$NaCl$$ is 58.5 g $$mol^{-1}$$
          Molar mass of $$O_{2}$$ is 32 g $$mol^{-1}$$

The amount of calcium oxide produced on heating 150 kg limestone (75% pure) is ______ kg. (Nearest integer)
Given : Molar mass (in g $$mol^{-1}$$) of $$Ca-40, O-16, C-12$$

A metal complex with a formula $$MCl_4 \cdot 3NH_3$$ is involved in $$sp^3d^2$$ hybridisation. It upon reaction with excess of $$AgNO_3$$ solution gives 'x' moles of AgCl. Consider 'x' is equal to the number of lone pairs of electron present in central atom of $$BrF_5$$. Then the number of geometrical isomers exhibited by the complex is ______.

The molar conductance of an infinitely dilute solution of ammonium chloride was found to be 185 S cm$$^2$$ mol$$^{-1}$$ and the ionic conductance of hydroxyl and chloride ions are 170 and 70 S cm$$^2$$ mol$$^{-1}$$, respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is 85.5 S cm$$^2$$ mol$$^{-1}$$, its degree of dissociation is given by $$x \times 10^{-1}$$. The value of x is ______. (Nearest integer)

x mg of $$Mg(OH)_2$$ (molar mass = 58) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of x is ____ mg. (Nearest integer)
(Given : $$Mg(OH)_{2}$$  is assumed to dissociate completely in $$H_{2}O$$)