NTA JEE Main 2025 April 4th Shift 1

In Dumas' method for estimation of nitrogen 1g of an organic compound gave 150 mL of nitrogen collected at 300K temperature and 900 mm Hg pressure. The percentage composition of nitrogen in the compound is ________ % (nearest integer). (Aqueous tension at 300 K = 15 mm Hg)

$$KMnO_4$$ acts as an oxidising agent in acidic medium. 'X' is the difference between the oxidation states of Mn in reactant and product. 'Y' is the number of 'd' electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The value of X + Y is ________.

Fortification of food with iron is done using $$FeSO_4 \cdot 7H_2O$$. The mass in grams of the $$FeSO_4 \cdot 7H_2O$$ required to achieve 12 ppm of iron in 150 kg of wheat is ________ (Nearest Integer) [Given: Molar mass of Fe, S and O respectively are 56, 32 and 16 g mol$$^{-1}$$]

The pH of a 0.01 M weak acid HX ($$K_a = 4 \times 10^{-10}$$) is found to be 5. Now the acid solution is diluted with excess of water so that the pH of the solution changes to 6. The new concentration of the diluted weak acid is given as $$x \times 10^{-4}$$ M. The value of x is ________ (nearest integer).

The total number of hydrogen bonds of a DNA-double Helix strand whose one strand has the following sequence of bases is ________.
5' - G - G - C - A - A - A - T - C - G - G - C - T - A - 3'