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Questions >> JEEMAIN and NEET >> Chemistry

Chemistry

1gm of $Fe_2O_3$ solid of 55.2% purity is dissolved in acid and reduced by heating the solution with Zn dust.The resultant solution is cooled and made up to 100ml,25ml of this solution requires 17ml of 0.0167M solution of an oxidant.Calculate the number of electrons taken up by the oxidant in the above reaction.

asked Jan 8, 2014 by sreemathi.v

1 answer

25ml of a solution containing HCl and $H_2SO_4$ required for neutralized 24.10ml of N/2 caustic soda solution.25ml of the same solution on precipitation with $BaCl_2$ yielded 0.5218gm $BaSO_4$.What wt of each acid is contained in one litre of the solution?

asked Jan 8, 2014 by sreemathi.v

1 answer

$0.5gm$ of $H_2SO_4$(oleum) is diluted with water.This solution is completely neutralized by 26.4ml of 0.4N NaOH.Find the % of free $SO_3$ in the sample.

asked Jan 8, 2014 by sreemathi.v

1 answer

A sample of chalk $(CaCO_3)$ is contaminated with calcium sulphate $(CaSO_4)$ 1gm of the solid mixture is dissolved in 230ml of N/10 HCl; 40ml of N/10 NaOH is required to neutralize the excess of acid.Find the percentage of chalk in the mixture.

asked Jan 8, 2014 by sreemathi.v

1 answer

A mixture of FeO and $Fe_3O_4$ when heated in air to a constant weight,gains 5% of its weight,Find the composition of the initial mixture.

asked Jan 8, 2014 by sreemathi.v

1 answer

A mixture of Al and Zn weighing 1.67g was completely dissolved in acid and evolved 1.69litre of $H_2$ at NTP.What was the weight of Al in original mixture?

asked Jan 8, 2014 by sreemathi.v

1 answer

1g sample of washing soda was dissolved in 50ml of 1.0M HCl.The excess acid required for neutralization 21.13ml of 1.018M $Ba(OH)_2$.Compute the degree of hydration of washing soda.

asked Jan 7, 2014 by sreemathi.v

1 answer

0.75 mole of solid $A_4$ and 2 mole of gaseous $O_2$ are heated to react completely in sealed vessel to produce only one gaseous compound B.After the compound is formed the vessel is brought to initial temperature,the pressure is found to half the initial pressure.What is molecular formula of compound?

asked Jan 7, 2014 by sreemathi.v

1 answer

A mixture of KOH and $Na_2CO_3$ solution required 15ml of N/20 HCl using phenolphthalein as indicator .The same amount of alkali mixture when titrated using methyl orange as an indicator required 25ml of same acid.Calculate the amount of KOH and $Na_2CO_3$ present in solution.

asked Jan 7, 2014 by sreemathi.v

1 answer

Approximately 45.0litre of 4.360M HCl were required for several experiments.How many litre of concentrated acid (37.5% by wt HCl) will be required?The specific gravity of conc. acid was $1.1875gml^{-1}$

asked Jan 7, 2014 by sreemathi.v

1 answer

A solution contains 4g of $Na_2CO_3$ and NaCl 250ml.25ml of this solution required 50ml of N/10 HCl for complete neutralization.Calculate % composition of mixture.

asked Jan 7, 2014 by sreemathi.v

1 answer

$1.575g$ of oxalic acid $(COOH)_2XH_2O$ are dissolved in water and the volume made upto 250ml.On titration 16.68ml of this solution requires 25ml of N/15 NaOH solution for complete neutralization.

asked Jan 7, 2014 by sreemathi.v

1 answer

A sample containing 0.4775g of $(NH_4)_2C_2O_4$ and inert materials was dissolved in water and made strongly alkaline with KOH ,which converted $NH_4^+$ to $NH_3$.The liberated ammonia was distilled into exactly 50.0ml of 0.05035M $H_2SO_4$.The excess $H_2SO_4$ was back titrated with 11.3ml of 0.1214M $NaOH$.Calculate percent of N,percent of $(NH_4)_2C_2O_4$.(Mol.wt of $(NH_4)_2C_2O_4=124.10$ and at .wt.of N=14.0078)

asked Jan 7, 2014 by sreemathi.v

1 answer

$2.0g$ of a mixture of carbonate ,bicarbonate and chloride of sodium on heating produced 56ml of $CO_2$ at NTP 1.6g of the same mixture required 25ml of 1N HCl solution for neutralization.Calculate percentage of each component present in mixture

asked Jan 7, 2014 by sreemathi.v

1 answer

$8.0575\times 10^{-2}Kg$ of Glauber's salt is dissolved in water to obtain $1dm^3$ of a solution of density 1077.2$Kgm^{-3}$.Calculate the molarity ,molality and mole fraction of $Na_2SO_4$ in solution.

asked Jan 7, 2014 by sreemathi.v

1 answer

The density (in $gml^{-1}$) of a 3.60M sulphuric acid solution that is 29% $H_2SO_4$.(Molar mass=98$gmol^{-1}$) by mass will be

asked Jan 7, 2014 by sreemathi.v

1 answer

A drop (0.05ml) of 12M HCl is spread over a thin sheet of aluminum foil (thickness 0.10mm and density of Al=2.70g/ml).Assuming whole of the HCl is used to dissolve Al,what will be the maximum area of hole produced in foil?

asked Jan 7, 2014 by sreemathi.v

1 answer

Calculate molality of 1 litre solution of $93\%$ $H_2SO_4$ by volume.The density of solution is $1.84\; g$ $mL^{-1}$

asked Jan 7, 2014 by sreemathi.v

1 answer

A 6.90M solution of KOH in water has 30% by weight of KOH. Calculate the density of the solution.

asked Jan 7, 2014 by sreemathi.v

1 answer

A piece of Al weighing $2.7g$ is titrated with $75\;ml$ of $H_2SO_4$ (specific gravity = $1.18gmL^{-1}$ and $24.7%$ $H_2SO_4$ by weight). After the metal is completely dissolved, the solution is diluted to $400\;ml$. Calculate molarity of free $H_2SO_4$ in solution.

asked Jan 7, 2014 by sreemathi.v

1 answer

$1\;g$ of impure $Na_2CO_3$ is dissolved in water and the solution is made upto $250\;ml$. To $50\;ml$ of this made up solution, $50\;ml$ of $0.1\;N\; HCl$ is added and the mixture after shaking well, required $10\;ml$ of $0.16\;N\; NaOH$ solution for complete neutralization. Calculate $\%$ purity of the sample of $Na_2CO_3$

asked Jan 7, 2014 by sreemathi.v

1 answer

4.08g of a mixture of BaO and unknown carbonate $(MCO_3)$ was heated strongly.The residue of 3.64g was dissolved in 100ml of 1N HCl.The excess acid required 16ml of 2.5N NaOH solution for complete neutralization.Identify metal

asked Jan 7, 2014 by sreemathi.v

1 answer

A small amount of $CaCO_3$ completely neutralized 525ml of N/10 HCl and no acid is left at the end.After converting all calcium chloride to $CaSO_4$,how much plaster of paris can be obtained?

asked Jan 7, 2014 by sreemathi.v

1 answer

25ml of a solution of $Na_2CO_3$ having a specific gravity of $1.25ml^{-1}$ required 32.9ml of a solution of HCl containing 109.5g of the acid per litre for complete neutralization .Calculate the volume of 0.84N $H_2SO_4$ that will be completely neutralized by 125g of $Na_2CO_3$ solution.

asked Jan 7, 2014 by sreemathi.v

1 answer

$1.387g$ of a sample containing KCl and $NH_4Cl$ is heated until constant weight.The residue is dissolved in 20ml of N/10 $AgNO_3$ solution.Calculate % of chlorine in mixture.

asked Jan 7, 2014 by sreemathi.v

1 answer

1.20g sample of $Na_2CO_3$ and $K_2CO_3$ was dissolved in water to form 100ml of a solution.20ml of this solution required 40ml of 0.1N HCl for complete neutralization.Calculate the weight of $Na_2CO_3$ in mixture. If another 20 ml of this solution is treated with excess of $BaCl_2$,what will be the weight of precipitate?

asked Jan 6, 2014 by sreemathi.v

1 answer

A mixture of ethane $(C_2H_6)$ and ethene $(C_2H_4)$ occupies 40 litre at 1.00atm and at 400k.The mixture reacts completely with 130g of $O_2$ to produce $CO_2$ and $H_2O$.Assuming ideal gas behavior ,Calculate the mole fractions of $C_2H_4$ and $C_2H_6$ in the mixture.

asked Jan 6, 2014 by sreemathi.v

1 answer

Consider following reaction: $Mg(s)+2HCl(aq)\rightarrow H_2(g)+MgCl_2(aq)$.The rate of this reaction increases when more magnesium is added.This change is due to

asked Dec 19, 2013 by sreemathi.v

1 answer

Consider the reaction $2H_2O_2(aq)\rightarrow 2H_2O(l)+O_2(g)$ wen 1g of KI is added to $H_2O_2$,bubbles of $O_2$ are produced at an increased rate.When reaction is complete,mass of KI is 1g.The KI is a

asked Dec 19, 2013 by sreemathi.v

1 answer

For reaction $X+Y\rightarrow Z$ the reaction rate is found to depend only upon concentration of X. A plot of $\large\frac{1}{[X]}$ vs time gives a straight line. What is rate law for this reaction?

asked Dec 19, 2013 by sreemathi.v

1 answer

Which of following is incorrect?

asked Dec 19, 2013 by sreemathi.v

1 answer

Which of following statements is incorrect for a first order reaction, where $T_x$ is the time taken for the reactant to drop by that % number.

asked Dec 19, 2013 by sreemathi.v

1 answer

What is the relation between half life ($t_{1/2}$) and temperature for an $n^{th}$ order reaction ;$n > 2$

asked Dec 19, 2013 by sreemathi.v

1 answer

The rate law for decomposition of $N_2O_5: N_2O_5\rightarrow 2NO_2+\large\frac{1}{2}$$O_2$ is consistent with observed rate law.If $k'=5\times 10^{-4}s^{-1}$ the time required for $[N_2O_5]$ be reduced to 10% of its original value.

asked Dec 19, 2013 by sreemathi.v

1 answer

For thermal decomposition of ozone to oxygen:Step (i):$O_3\;\;\;\overset{\overset{k_1}{\rightleftharpoons}}{k_{-1}}\;\;\; O_2+O$.Step (ii):$O_3+O\;\;\;\underrightarrow{k_2}\;\;\;2O_2$ then rate will be $\{k_{-1}[O_2] > > k_2[O_3]\}$

asked Dec 19, 2013 by sreemathi.v

1 answer

The ratio of $\large\frac{t_{1/2}}{t_{3/4}}$ for $n^{th}$ order is

asked Dec 19, 2013 by sreemathi.v

1 answer

The inactivation of a viral preparation is found to be first order reaction.If in beginning $1.5\%$ of virus is inactivated then calculate time required for 50V inactivation.

asked Dec 19, 2013 by sreemathi.v

1 answer

For following data for hydrolysis of benzene diazonium chloride $C_6H_5-N=N-Cl+H_2O\rightarrow C_6H_5OH+HCl+N_2(g)$, What is the first order calculate rate constant?

asked Dec 19, 2013 by sreemathi.v

1 answer

The gas -phase thermal decomposition of one mole of $(CH_3)_3CO_2C(CH_3)_3$ in a constant volume apparatus yields two moles of acetone and one mole of ethane.If the reaction obeys ${1^{st}}$ order then which of the following is true?

asked Dec 19, 2013 by sreemathi.v

1 answer

From following data of decomposition of ammonium nitrate in aqueous solution, Determine the order of reaction:

asked Dec 19, 2013 by sreemathi.v

1 answer

For reversible reaction,$X\;\;\overset{\overset{k_1}{\rightleftharpoons}}{k_2}\;\;Y$.$k_1=2hr^{-1}$ and $\large\frac{[X_{eq}]}{[Y_{eq}]}$$=6$.If $[X_0]=2M,[Y_0]=0M$.What will be the the concentration of Y after 1hr?

asked Dec 19, 2013 by sreemathi.v

1 answer

An optically active compound A upon acid catalyzed hydrolysis yield two optically active compound B & C by first order kinetics.It is given that $[\alpha_0]$ for $A,B$ & C are $60^o,40^o$ & $-80^o$ respectively.If observed both of the mixture after 20 minute was $5^o$ while after completion of the reaction it was $-20^o$.What is $t_{1/2}$ of reaction?

asked Dec 18, 2013 by sreemathi.v

1 answer

A solution of A is mixed with equal volume of a solution of B containing the same number of moles,for reaction $A+B\rightarrow C$.At the end of 1 hour,A is 75% reacted.How much of A will be left unreacted at the end of 2hours if the reaction is first order in A & zero order in B.

asked Dec 18, 2013 by sreemathi.v

1 answer

Which one of the following is an amine hormone ?

asked Dec 18, 2013 by thanvigandhi_1

0 answers

Which one of the following statements is not true?

asked Dec 18, 2013 by thanvigandhi_1

1 answer

In a reaction of aniline a coloured product C was obtained

asked Dec 18, 2013 by thanvigandhi_1

0 answers

Acetophenone when reacted with a base, $ C_2H_5ONa,$ yields a stable compound which has the structure :

asked Dec 18, 2013 by thanvigandhi_1

0 answers

In a $S_N2$ substitution reaction of the type $ R-B+CI^- \underrightarrow {DMF} R-CI+Br^+,$ which one of the following has the highest reactivity rate :

asked Dec 18, 2013 by thanvigandhi_1

0 answers

An organic compound contains carbon, hydrogen and oxygen. Its elemental analysis gave C, 38.71% and H, 9.67% . Th empirical formula of the compound would be :

asked Dec 18, 2013 by thanvigandhi_1

1 answer

Which one of the following is most reactive towards electrophilic attack?

asked Dec 18, 2013 by thanvigandhi_1

0 answers

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