JEE Mains · Chemistry · STD 12 - 10. Biomolecules
Observation of "Rhumann 's purple " is a confirmatory test for the presence of
- A Starch
- B Reducing sugar
- C Protein
- D Cupric ion
Answer & Solution
Correct Answer
(C) Protein
Step-by-step Solution
Detailed explanation
Ninhdrin is often used to detect \(\alpha \) - amino acids and also free amino and carboxylic acid group on proteins and peptides. when about \(0.5\,ml\) of a \(0.1\%\) solution of ninhydin is boiled for one or two minutes with a few \(\,ml\) of dilute amino acid or protein…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- Consider the transition metal ions \(Mn^{3+}\) \(Cr^{3+}\) \(Fe^{3+}\) and \(Co^{3+}\) and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes isJEE Mains 2026 Medium
- The pairs among \(A = [\text{SO}_3^{2-}, \text{CO}_3^{2-}]\), \(B = [\text{O}_2^{2-}, \text{F}_2]\), \(C = [\text{CN}^-, \text{CO}]\), \(D = [\text{NH}_3, \text{H}_3\text{O}^+]\) and \(E = [\text{MnO}_4^{2-}, \text{CrO}_4^{2-}]\) that do not have similar Lewis dot structure areJEE Mains 2026 Medium
- When ' \(\mathrm{x}\) ' \(\times 10^{-2} \mathrm{~mL}\) methanol (molar mass \(=32 \mathrm{~g}\); density \(=0.792 \mathrm{~g} / \mathrm{cm}^3\) ) is added to \(100 \mathrm{~mL}\) water (density \(=1 \mathrm{~g} / \mathrm{cm}^3\) ), the following diagram is obtained. (Image) \(x=\) _______ (nearest integer) [Given: Molal freezing point depression constant of water at \(273.15 \mathrm{~K}^2\) is \(1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\) ]
JEE Mains 2024 Medium - A compound 'X' absorbs 2 moles of hydrogen and 'X' upon oxidation with \(KMnO _4 \mid H ^{+}\)gives
The total number of \(\sigma\) bonds present in the compound 'X' is ________.JEE Mains 2025 Easy - In order to oxidise a mixture of \(1\) mole each of \(FeC_2O_4\), \(Fe_2(C_2O_4)_3\), \(FeSO_4\) and \(Fe_2(SO_4)_3\) in acidic medium, the number of moles of \(KMnO_4\) required isJEE Mains 2026 Hard
- Among \(Co ^{3+}, Ti ^{2+}, V ^{2+}\) and \(Cr ^{2+}\) ions, one if used as a reagent cannot liberate \(H _{2}\) from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is \(......B.M\). (Nearest integer)JEE Mains 2022 Medium
More PYQs from JEE Mains
- In a meter bridge experiment \(\mathrm{S}\) is a standard resistance. \(\mathrm{R}\) is a resistance wire. It is found that balancing length is \(l=25 \;\mathrm{cm} .\) If \(\mathrm{R}\) is replaced by a wire of half length and half diameter that of \(\mathrm{R}\) of same material, then the balancing distance \(\left.l^{\prime} \text { (in } \mathrm{cm}\right)\) will now be
JEE Mains 2020 Hard - \(25\, mL\) of the given \(HCl\) solution requires \(30\, mL\) of \(0.1\, M\) sodium carbonate solution. What is the volume of this \(HCl\) solution required to titrate \(30\, mL\) of \(0.2\, M\) aqueous \(NaOH\) solution? .............. \(\mathrm{mL}\)JEE Mains 2019 Hard
- The area of the region enclosed between the circles \( x^{2}+y^{2}=4 \) and \( x^{2}+(y-2)^{2}=4 \) is:JEE Mains 2026 Medium
- Let PQ be a chord of the hyperbola \( \frac{x^{2}}{4}-\frac{y^{2}}{b^{2}}=1 \), perpendicular to the x-axis such that OPQ is an equilateral triangle, O being the centre of the hyperbola. If the eccentricity of the hyperbola is \( \sqrt{3} \) then the area of the triangle OPQ is:JEE Mains 2026 Medium
- Let \(x, y, z\) be positive real numbers such that \(x + y + z = 12\) and \(x^3y^4z^5 = (0. 1 ) (600)^3\). Then \(x^3 + y^3 + z^3\) is equal toJEE Mains 2016 Hard
- The mechanism of \(S _{ N } 1\) reaction is given as \(R - X \rightarrow R ^{\oplus} X ^{\ominus} \rightarrow R ^{\oplus} \| X ^{\ominus} \stackrel{ Y^\ominus }{\rightarrow} R - Y + X ^{\ominus}\) Ion pair Solvent separated ion pair A student writes general characteristics based on the given mechanism as: \((a)\) The reaction is favoured by weak nucleophiles \((b)\) \(R^ \oplus\) would be easily formed if the substituents are bulky \((c)\) The reaction is accompained by recemization \((d)\) The reaction is favoured by non-polar solvents. Which observations are correct \(?\)JEE Mains 2020 Medium