JEE Main entrance exam Question Bank Solutions for Chemistry (JEE Main)

Lassaigne's test for the detection of nitrogen fails in ______.

A solution is prepared by mixing 250 ml toluene (C₇H₈) and 8.4 g thiophene (C₄H₄S). Then molality of thiophene in the solution is ______. [Given : Density of toluene = 0.8 g/ml, Density of thiophene = 1.2 g/ml]
[Multiply your answer by 10]

A 50 L gas stream was passed through a solution containing Cd²⁺ where H₂S (in gas stream) was retained as CdS. The mixture was acidified and treated with 50 ml of 0.004 M I₂. After the reaction \[\ce{S^{2-} + I2 -> S(s) + 2I-}\] was complete, the excess iodine was treated with 15 ml of 0.01 M thiosulphate. The concentration of H₂S in ppm will be ______. Use density of gas stream = 1.7 gm/L.

A gem dichloride is formed in the reaction except ______.

Lauryl alcohol is obtained from coconut oil and is used to make detergent. A solution of 5 g of Lauryl alcohol in 200 g of benzene freezes at 4°C. The approximate molar mass of Lauryl alcohol will be ______.

Given, K_f of benzene = 5.1°C/molal, Freezing point of benzene = 5.5°C.

[Give your answer after division by 17]

A gaseous mixture was passed at the rate of 2.5 L/min through a solution of NaOH for a total of 1 hour. The SO₂ in the mixture was retained as sulphite ion:

\[\ce{SO2(g) + 2OH- -> SO3^2 - (g) + H2O(l)}\]

After acidification with HCl the sulphite was titrated with 5 ml of 0.003 M KIO₃

\[\ce{IO_3^- + 2H2SO3 + 2Cl- -> 2SO^{2-}_4 + ICl^-_2 + 2H+ + H2O}\]

The concentration of SO₂ will be ______ ppm if density of gaseous mixture is 1.6 gm/L.

\[\ce{N2 + 3H2 <=> 2NH3 }\]

1 mole N₂ and 3 mole H₂ are present at start in 1L flask. At equilibrium NH₃ formed required 100 mL of 5M HCl for neutralisation hence K_C is ______.

When SO₂ is passed through acidified K₂Cr₂O₇ solution ______.

When 2-alkyne is treated with sodamide product will be ______.

A 10 ml of (NH₄)₂ SO₄ was treated with an excess of NaOH. The evolved NH₃ gas absorbed in 50 ml of 0.1 N HCl. 20 ml of 0.1 N NaOH was required to neutralise the remaining HCl. The strength of (NH₄)₂ SO₄ in the solution is ______ g/L.

Hydrogen has three isotopes: protium (¹H), deuterium (²H or D) and tritium (³H or T). They have nearly the same chemical properties but different physical properties. They differ in ______.

Which one of the following statements for D.I. Mendeleev is incorrect?

Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Lithium salts are hydrated.

Reason (R) : Lithium has higher polarising power than other alkali metal group members.

In the light of the above statements, choose the most appropriate answer from the options given below :

The correct order of conductivity of ions in water is ______.

KO₂ (potassium super oxide) is used in oxygen cylinders in space and submarines because it ______.

The acid that is believed to be mainly responsible for the damage of Taj Mahal is ______.

Given below are two statements:

Statement I: Phenols are weekly acidic.

Statement II: Therefore they are freely soluble in NaOH solutions and are weaker acids than alcohols and water.

Choose the most appropriate options:

(A) \[\ce{HOCl + H2O2 -> H3O^+ + Cl^- + O2}\]

(B) \[\ce{I2 + H2O2 + 2OH^- -> 2I^- + 2H2O + O2}\]

Choose the correct option.

Given below are two statements:

Statement I: The E° value for \[\ce{\frac{Ce^{4+}}{Ce^{3+}}}\] is +1.74 V.

Statement II: Ce is more stable in Ce⁴⁺ state than Ce³⁺ state.

In the light of the above statements, choose the correct answer from the options given below:

\[\ce{2MnO^-4 + {b}C2O^{2-}4 + {c}H^+ -> {x}Mn^{2+} + {y}CO2 + {z}H2O}\]

If the above equation is balanced with integer coefficients, the value of c is ______. (Round off to the Nearest Integer).