Recent questions tagged class11

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

The equation of the plane that meets the coordinate axes at the points $A,B,C$ respectively and the centroid of the $\Delta\:ABC$ is $(2,1,5)$ is ?

asked Jan 7, 2014 by rvidyagovindarajan_1

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

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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

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$1.575g$ 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

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

The probability that a number selected at random from the set of numbers { 1,2,3,.....100} is a cube is

asked Jan 6, 2014 by thanvigandhi_1

1 answer

If S is a sample space $P(A) = \large\frac{1}{3} P(B)\: and \: S = A \cup B$ where A,B are two mutually exclusive events, then $P(A)=$

asked Jan 6, 2014 by thanvigandhi_1

1 answer

A line makes angle $\theta$ with both $x\:axis$ and $z\:axis$. If it makes angle $\alpha$ with $y\:axis$ and $\sin^2\alpha=2 \sin^2\theta$ then $\cot^2\theta=?$

asked Jan 6, 2014 by rvidyagovindarajan_1

1 answer

A tetrahedron has vertices $O(0,0,0),\:A(1,2,1)\:B(2,1,3)\:C(-1,1,2)$. The angle between the faces $OAB$ and $ABC$ is ?

asked Jan 6, 2014 by rvidyagovindarajan_1

1 answer

The value of $k$ for which the line $\overrightarrow r=(4\hat i+2\hat j-\hat k)+\lambda(\hat i-k\hat j+2\hat k)$ lies on the plane $2x-4y+z=3$ is ?

asked Jan 6, 2014 by rvidyagovindarajan_1

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

Let P be the probability of happening any event and Q its failure, then the total chance of $ r$ success in $n$ trials is

asked Jan 6, 2014 by thanvigandhi_1

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The probability that a non - leap year has 53 sundays is

asked Jan 6, 2014 by thanvigandhi_1

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The chance of throwing a total of 3 or 5 or 11 wih two dice is

asked Jan 6, 2014 by thanvigandhi_1

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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

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1. Mycoplasma are a group of fungus. 2. They are devoid of cell walls 3. They are highly pleomorphic, with fixed shape and size.

asked Jan 6, 2014 by pady_1

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1. Bacteria show a range in the number and arrangement of flagella. 2. Bacterial flagellum is composed of three parts – filament, hook and basal body. 3. The filament is the longest portion and extends from the cell surface to the outside. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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Glycocalyx :- 1. It is of same composition and thickness among different bacteria though it may differ whethe tightly or loosely attached. 2. It could be a loose sheath called the capsule in some 3. While in others it may be tightly bound and tough, called the slime layer. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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1. Prokaryotes and unicellilar eukaryotes have something unique in the form of inclusions. 2. A specialised differentiated form of cell membrane called mesosome is the characteristic of prokaryotes. 3. They are essentially aggregations of cytoplasmic proteins. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

1 answer

Prokaryotes: 1. Most prokaryotes do not have a cell wall. 2. The fluid matrix filling the cell is the cytoplasm. 3. There is no well-defined nucleus. 4. The genetic material is basically naked, not enveloped by a nuclear membrane. Regarding 1,2,3 and 4:

asked Jan 6, 2014 by pady_1

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1. Prokaryotic cells are generally smaller 2. Thet multiply more rapidly than the eukaryotic cells. 3. They may vary greatly in shape and size. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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1. Human red blood cells are about 11.0 μm in diameter. 2. Nerve cells are some of the largest cells. 3. Cells also vary greatly in their shape; they may be disc-like, polygonal, columnar, cuboid, thread like, or even irregular. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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1. Nucleus is a dense membrane bound structure. 2. Nucleus contains the chromosomes 3. Chromosomes in turn contain the genetic material, DNA. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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1. The onion cell is a typical plant cell 2. It has a distinct cell wall as its outer boundary 3. Cell wall is just within the cell membrane. 4. The cells of the human cheek have an outer membrane as the delimiting structure of the cell. Regarding 1,2,3 and 4:

asked Jan 6, 2014 by pady_1

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CELL THEORY : 1. Rudolf Virchow first explained that cells divided 2. He explained that new cells are formed from pre-existing cells (Omnis cellula-e cellula). 3. He modified the hypothesis of Schleiden and Schwann to give the cell theory a final shape. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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CELL THEORY : 1. Matthias Schleiden, a German botanist observed that all plants are composed of different kinds of cells which form the tissues of the plant. 2. Theodore Schwann (1839), a British Zoologist, studied different types of animal cells and reported that cells had a thin outer layer (‘plasma membrane’). 3. Theodore Schwann also concluded that the presence of cell wall is a unique character of the plant cells. 4. Schwann proposed the hypothesis that the bodies of animals and plants are composed of cells and products of cells. Regarding 1,2,3 and 4:

asked Jan 6, 2014 by pady_1

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Regarding G.N. RAMACHANDRAN: 1. He was the founder of the ‘Madras school’ of conformational analysis of biopolymers. 2. His discovery of the triple helical structure of collagen published in Nature in 1954 3. His analysis of the allowed conformations of proteins through the use of the ‘Ramachandran plot’ rank among the most outstanding contributions in structural biology. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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Class – Mammalia : 1. Sexes are separate 2. Fertilisation is internal. 3. They are always viviparous 4. Development is direct. Regarding 1,2,3 and 4:

asked Jan 6, 2014 by pady_1

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Class – Mammalia : 1. Heart is four- chambered. 2. Respiration is by lungs. 3. They are poikilothermous. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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Class – Mammalia : 1. The skin of mammals is unique in possessing hair. 2. External ears or pinnae are absent in most species. 3. Different types of teeth are present in the jaw. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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Class – Aves : 1. Sexes are separate. 2. Fertilisation is external. 3. They are oviparous 4. Development is direct. Regarding 1,2,3 and 4:

asked Jan 6, 2014 by pady_1

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Class – Aves : 1. Heart is completely four- chambered. 2. Respiration is by lungs. 3. Air sacs connected to lungs supplement respiration. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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Class – Aves : 1. The characteristic features of Aves are the presence of feathers 2. Most of them can fly 3.Ostrich is one of the flightless birds. Regarding 1,2 and 3:

asked Jan 6, 2014 by pady_1

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Class – Reptilia : 1. Sexes are separate. 2. Fertilisation is internal. 3. They are oviparous 4. Development is direct. Regarding 1,2,3 and 4:

asked Jan 6, 2014 by pady_1

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