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Chemistry
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Showing 1–25 of 31 questions
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The reaction that does not give benzoic acid as the major product is:$K_2Cr_2O_7$ and $KMnO_4/H^+$ oxidise benzyl alcohol to benzoic acid, and acetophenone undergoes the haloform reaction with NaOCl to give benzoic acid (+ $CHCl_3$). PCC is a mild oxidising agent and stops at benzaldehyde ($C_6H_5CHO$).
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Which structure(s) of proteins remain(s) intact during denaturation process?During denaturation the $2^\circ$ and $3^\circ$ structures are destroyed but the $1^\circ$ structure remains intact.
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The polymer that is used as a substitute for wool in making commercial fibres is:Polyacrylonitrile is used as a substitute for wool in making commercial fibres such as Orlon or Acrilan.
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The artificial sweetener stable at cooking temperature and does not provide calories is:Sucralose is stable at cooking temperature and does not provide calories.
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The liquified gas that is used in dry cleaning along with a suitable detergent is:
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The hydrolysis reaction that takes place at the slowest rate, among the following is:Aryl halides do not undergo nucleophilic substitution easily at room temperature (partial double bond character of C-Cl due to resonance), so the chlorotoluene reacts slowest.
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When vapours of a secondary alcohol is passed over heated copper at 573 K, the product formed is:$CH_3-CH(OH)-CH_3\xrightarrow{Cu/573\ K}CH_3-CO-CH_3$. Secondary alcohols are dehydrogenated to ketones.
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Match the oxide given in Column A with its property given in Column B. Which option has all correct pairs?
Pick the matching item from Column II for each row.
Column I
- I. $Na_2O$
- II. $Al_2O_3$
- III. $N_2O$
- IV. $Cl_2O_7$
Column II
- A. Neutral
- B. Basic
- C. Acidic
- D. Amphoteric
Correct answer: I → B, II → D, III → A, IV → C
$Na_2O\rightarrow$ basic; $Al_2O_3\rightarrow$ amphoteric; $N_2O\rightarrow$ neutral; $Cl_2O_7\rightarrow$ acidic. -
The alkane that gives only one mono-chloro product on chlorination with $Cl_2$ in presence of diffused sunlight is:
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Which of the following compounds is used in cosmetic surgery?
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Identify the incorrect statement.The contaminated undesired material present in an ore is called gangue; gangue is not the ore itself.
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A compound 'X' upon reaction with $H_2O$ produces a colorless gas 'Y' with rotten fish smell. Gas 'Y' is absorbed in a solution of $CuSO_4$ to give $Cu_3P_2$ as one of the products. Predict the compound 'X'$Ca_3P_2+6H_2O\rightarrow3Ca(OH)_2+2PH_3$ (colourless gas Y). $3CuSO_4+2PH_3\rightarrow Cu_3P_2+3H_2SO_4$. Hence X is calcium phosphide, $Ca_3P_2$.
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Which of the following oxoacids of phosphorus has strongest reducing property?Reducing property $\propto$ number of P-H bonds. $H_3PO_2$ has two P-H bonds, the maximum among these.
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Identify the correct formula of oleum from the followingOleum is pyrosulphuric acid, $H_2S_2O_7$.
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When neutral or faintly alkaline $KMnO_4$ is treated with potassium iodide, iodide ion is converted into 'X'. 'X' isIn neutral or faintly alkaline medium: $2MnO_4^-+I^-+H_2O\rightarrow2MnO_2+IO_3^-+2OH^-$. So X is iodate, $IO_3^-$.
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A first order reaction has a rate constant of $2.303\times10^{-3}$ s$^{-1}$. The time required for 40 g of this reactant to reduce to 10 g will be [Given that $\log_{10}2=0.3010$]$t_{1/2}=\frac{0.693}{k}=\frac{0.693}{2.303\times10^{-3}}=301$ s. 40 g to 10 g is two half-lives (75% completion): $t=2\times301=602$ s.
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For a reaction, activation energy $E_a=0$ and the rate constant at 200 K is $1.6\times10^6$ s$^{-1}$. The rate constant at 400 K will be [Given that gas constant R = 8.314 J K$^{-1}$ mol$^{-1}$]$\log\frac{K_2}{K_1}=\frac{E_a}{2.303R}\left(\frac{1}{T_1}-\frac{1}{T_2}\right)=0$ since $E_a=0$. So $K_2=K_1=1.6\times10^6$ s$^{-1}$.
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The correct option representing a Freundlich adsorption isotherm isFreundlich isotherm: $\frac{x}{m}=kp^{1/n}$ with $0<\frac{1}{n}<1$. Hence $\frac{x}{m}=kp^{0.3}$.
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Which of the following is paramagnetic?According to MOT, $O_2$ has two unpaired electrons in the $\pi^*2p$ orbitals and is paramagnetic; $N_2$, $H_2$ and $Li_2$ have all electrons paired.
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Crude sodium chloride obtained by crystallisation of brine solution does not containCrude NaCl obtained by crystallisation of brine contains $Na_2SO_4$, $CaSO_4$, $CaCl_2$ and $MgCl_2$ as impurities, but not $MgSO_4$.
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Which of the alkali metal chloride (MCl) forms its dihydrate salt ($MCl\cdot2H_2O$) easily?$Li^+$ has the maximum hydration tendency, so LiCl forms the dihydrate $LiCl\cdot2H_2O$.
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The pH of 0.01 M NaOH (aq) solution will beNaOH is a strong base: $[OH^-]=10^{-2}$ M, $pOH=2$, $pH=14-2=12$.
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Which of the following cannot act both as Bronsted acid and as Bronsted base?HCl can only donate a proton, so it cannot act as a Bronsted base; the others are amphiprotic.
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The oxidation state of Cr in $CrO_6$ is:
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The number of hydrogen bonded water molecule(s) associated with $CuSO_4\cdot5H_2O$ is:In $CuSO_4\cdot5H_2O$, four water molecules are coordinated to $Cu^{2+}$ and only one water molecule is hydrogen bonded.