Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Some Basic Concepts of Chemistry question

2020 · 7 Jan · Shift 2 · Q4
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Chemistry
  4. /Some Basic Concepts of Chemistry
  5. /2020 · 7 Jan · Shift 2 · Q4

Some Basic Concepts of Chemistry question

2020 · 7 Jan · Shift 2 · Q4

JEE MainChemistrySome Basic Concepts of ChemistryMCQ+4 / −1
The ammonia (NH3NH_3NH3​) released on quantitative reaction of 0.6 g urea (NH2CONH2NH_2CONH_2NH2​CONH2​) with sodium hydroxide (NaOHNaOHNaOH) can be neutralized by :
  1. A
    200 ml of 0.02 N HCl
  2. B
    100 ml of 0.2 N HCl
  3. C
    100 ml of 0.1 HCl
  4. D
    200 ml of 0.4 N HCl
View written solutionFree

Correct answer: B

  1. Write the reaction

Urea reacts with sodium hydroxide as:

(NH2)2CO+2NaOH→Na2CO3+2NH3(NH_2)_2CO + 2NaOH \rightarrow Na_2CO_3 + 2NH_3(NH2​)2​CO+2NaOH→Na2​CO3​+2NH3​

So, 1 mole of urea gives 2 moles of NH3NH_3NH3​.

  1. Calculate moles of urea

Molar mass of urea, (NH2)2CO(NH_2)_2CO(NH2​)2​CO:

=12+16+2×14+4×1=60 g/mol= 12 + 16 + 2\times 14 + 4\times 1 = 60\,g/mol=12+16+2×14+4×1=60g/mol

Given mass of urea = 0.6 g0.6\,g0.6g

moles of urea=0.660=0.01\text{moles of urea} = \frac{0.6}{60} = 0.01moles of urea=600.6​=0.01
  1. Calculate moles of ammonia produced

From stoichiometry:

1 mol urea→2 mol NH31\text{ mol urea} \rightarrow 2\text{ mol } NH_31 mol urea→2 mol NH3​

Therefore,

0.01 mol urea→0.02 mol NH30.01\text{ mol urea} \rightarrow 0.02\text{ mol } NH_30.01 mol urea→0.02 mol NH3​
  1. Find acid required for neutralization

Neutralization reaction:

NH3+HCl→NH4ClNH_3 + HCl \rightarrow NH_4ClNH3​+HCl→NH4​Cl

Thus, 1 mole of NH3NH_3NH3​ requires 1 mole of HCl.

So required HCl = 0.020.020.02 mol.

Since HCl is monoprotic,

Normality=Molarity\text{Normality} = \text{Molarity}Normality=Molarity

Required equivalents of HCl = 0.020.020.02.

  1. Check each option

  • A: 200 mL200\,mL200mL of 0.02 N0.02\,N0.02N HCl

    equivalents=0.02×0.2=0.004\text{equivalents} = 0.02 \times 0.2 = 0.004equivalents=0.02×0.2=0.004

    Not sufficient.

  • B: 100 mL100\,mL100mL of 0.2 N0.2\,N0.2N HCl

    equivalents=0.2×0.1=0.02\text{equivalents} = 0.2 \times 0.1 = 0.02equivalents=0.2×0.1=0.02

    Exactly sufficient.

  • C: 100 mL100\,mL100mL of 0.1 N0.1\,N0.1N HCl

    equivalents=0.1×0.1=0.01\text{equivalents} = 0.1 \times 0.1 = 0.01equivalents=0.1×0.1=0.01

    Not sufficient.

  • D: 200 mL200\,mL200mL of 0.4 N0.4\,N0.4N HCl

    equivalents=0.4×0.2=0.08\text{equivalents} = 0.4 \times 0.2 = 0.08equivalents=0.4×0.2=0.08

    More than required, so not the exact neutralizing amount in a single-correct MCQ.

  1. Conclusion

The ammonia produced is exactly neutralized by:

B: 100 mL of 0.2 N HCl\boxed{\text{B: }100\,mL\text{ of }0.2\,N\,HCl}B: 100mL of 0.2NHCl​
PreviousNext

More from Some Basic Concepts of Chemistry

  • The volume (in mL) of 0.125 M AgNO3​ required to quantitatively precipitate chloride ions in 0.3 g of [Co(NH3​)6​]Cl3​ is ​. M[Co(NH3​)6​Cl3​] = 267.46 g/mol MAgNO3​ = 169.87 g/mol2020 · Numerical
  • Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required to achieve 10 ppm of iron in 100 kg of wheat is ​. Atomic weight : Fe = 55.85; S = 32.00; O = 16.002020 · Numerical
  • The molarity of HNO3​ in a sample which has density 1.4 g/mL and mass percentage of 63% is ​. (Molecular Weight of HNO3​ = 63)2020 · Numerical
  • The hardness of a water sample containing 10–3 M MgSO4​ expressed as CaCO3​ equivalents (in ppm) is ​. (molar mass of MgSO4​ is 120.37 g/mol)2020 · Numerical
  • 10.30 mg of O2​ is dissolved into a liter of sea water of density 1.03 g/mL. The concentration of O2​ in ppm is ​.2020 · Numerical
  • The percentage composition of carbon by mole in methane is :2019 · MCQ
  • For a reaction, N2​(g) + 3H2​(g) → 2NH3​(g) ; identify dihydrogen (H2​) as a limiting reagent in the following reaction mixtures.2019 · MCQ
  • What would be the molality of 20% (mass/ mass) aqueous solution of KI? (molar mass of KI = 166 g mol–1)2019 · MCQ