The following questions have appeared in JEE - Main / AIEEE. The Year in which the question appeared is mentioned after the question.
For the estimation of nitrogen, 1.4g of organic compound was digested by Kjeldahl metod and the evolved ammonia was absorbed in 60mL of 0.1M sulphuric acid. The unreacted acid required 20mL of 0.1M sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is
A) 3%
B) 5%
C) 6%
D) 10%
[2014]
The molarity of a solution obtained by mixing 750mL of 0.5M HCl with 250mL of 2M HCl will be
A) 1.00M
B) 1.75M
C) 0.975M
D) 0.875M
[2013]
A gaseous hydrocarbon gives upon combustion 0.72g of water and 3.08g of carbon dioxide. The empirical formula of the hydrocarbon is
A) \(C_3H_4\)
B) \(C_6H_5\)
C) \(C_7H_8\)
D) \(C_2H_4\)
[2013]
Consider the following reaction:
\[xMnO_4^- + yC_2O_4^{2-} + zH^+ \rightarrow xMn^{2+} + 2yCO_2 + \frac{z}{2}H_2O\]
The values of x, y and z in the reaction are, respectively
A) 2, 5 and 8
B) 2, 5 and 16
C) 5, 2 and 8
D) 5, 2 and 16
[2013]
The mass of potassium dichromate crystals required to oxidise 750mL of 0.6M Mohr’s salt solution is (Molar mass of \(K_2Cr_2O_7\) = 294, Mohr’s Salt = 392)
A) 2.2g
B) 0.49g
C) 0.45g
D) 22.05g
[2011]
What is the best description of the change that occurs when \(Na_2O\) is dissolved in water?
A) Oxidation Number of oxygen increases
B) Oxidation Number of sodium decreases
C) Oxide ion accepts a pair of electrons
D) Oxide ion donates a pair of electrons
[2011]
29.5mg of an organic compound containing nitrogen awas digested according to Kjeldahl’s method and the evolved ammonia was absorbed in 20mL of 0.1M HCl solution. The excess of the acid required 15mL of 0.1M NaOH solution for complete neutralization. The percentage of nitrogen in the compound is
A) 59.0%
B) 47.4%
C) 23.7%
D) 29.5%
[2010]
The amount of oxalic acid present in a solution can be determined by its titration with \(KMnO_4\) solution in the presence of \(H_2SO_4\). The titration gives unsatisfactory result when carried out in presence of HCl, because
A) HCl gets oxidised by oxalic acid to chlorine
B) HCl furnishes \(H^+\) ions in addition to those from oxalic acid
C) HCl reduces permanganate ion to \(Mn^{2+}\)
D) HCl oxidises oxalic acid to carbon dioxide and water
[2008]
Which of the following statements are true for the reaction \(2Al (s) + 6HCl (aq) \rightarrow 2Al^{3+}(aq) + 6Cl^- (aq) + 3H_2 (g)\)?
A) 11.2L of \(H_2(g)\) at STP is produced for every mole of \(HCl(aq)\) consumed
B) 6L of \(HCl(aq)\) is consumed for every 3L of \(H_2(g)\) produced
C) 33.6L of \(H_2(g)\) is produced regardless of temperature and pressure for every mole of Al that reacts
D) 67.2L of \(H_2(g)\) at STP is produced for every mole of Al that reacts
[2007]
How many moles of Magnesium Phosphate, \(Mg_3(PO_4)_2\) will contain 0.25 mole of oxygen atoms?
A) \(2 \times 10^{-2}\)
B) \(3.125 \times 10^{-2}\)
C) \(1.25 \times 10^{-2}\)
D) \(2.5 \times 10^{-2}\)
[2006]
Density of a 2.05M solution of acetic acid in water is 1.02g/mL. The molality of the solution is
A) 1.14 mol/kg
B) 3.28 mol/kg
C) 2.28 mol/kg
D) 0.44 mol/kg
[2006]
Which of the following chemical reactions depicts the oxidising behaviour of \(H_2SO_4\)?
A) \(2HI + H_2SO_4 \rightarrow I_2 + SO_2 + 2H_2O\)
B) \(Ca(OH)_2 + H_2SO_4 \rightarrow CaSO_4 + 2H_2O\)
C) \(NaCl + H_2SO_4 \rightarrow NaHSO_4 + HCl\)
D) \(2PCl_5 + H_2SO_4 \rightarrow2POCl_3 + SO_2Cl_2 + 2HCl\)
[2006]
If we consider that \(\frac{1}{6}\), in place of \(\frac{1}{12}\), mass of carbon atom is taken to be relative atomic mass unit, the mass of one mole of a substance will
A) decrease twice
B) increase two fold
C) remain unchanged
D) be a function of the molecular mass of the substance
[2005]
What volume of hydrogen gas at 273K and 1 atm pressure will be consumed in obtaining 21.6g of elemental boron from the reduction of \(BCl_3\) by \(H_2\) (atomic mass of B = 10.8)?
A) 89.6L
B) 67.2L
C) 44.8L
D) 22.4L
[2003]
With increase of temperature, which of the following will change?
A) Molality
B) Weight fraction of solute
C) Fraction of solute present in water
D) Mole Fraction
[2002]
The number of atoms in 558.5g of Fe (atomic mass of Fe = 55.85 g/mol) is
A) twice that in 60g of Carbon
B) \(6.02 \times 10^{22}\)
C) half that in 8g of He
D) \(558.5 \times 6.02 \times 10^{23}\)
[2002]
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