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Recent questions tagged medium
Questions
Chlorophyll,a green coloring matter contains 2.68% mg.The number of atoms of mg present 1g chlorophyll are
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q36
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
4.4g of $CO_2$ and $2.24$ litre of $H_2$ at STP are mixed in a container.The total number of molecules present in the container will be
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
stoichiometry
q35
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
224 ml of triatomic gas weights 1g at 173k and 1atm .The mass of one atom of this gas is
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q34
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
Weight of oxygen in $Fe_2O_3$ and FeO in the simple ratio for the same amount of Fe is
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
laws-of-chemical-combinations
q33
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
Two elements $X$ and $Y$ have atomic mass 75 and 16 respectively.They combine to give a compound having 75.8%X.The formula is
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q32
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
Two oxides of a metal contain 50% and 40% of metal M respectively.If the formula of first oxide is MO,+ve formula of $2^{nd}$ oxide will be
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q31
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
An organic compound containing C and it has 92.3% carbon .Its empirical formula is :
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q30
medium
asked
Oct 24, 2013
by
sreemathi.v
2
answers
A compound has an empirical formula $C_2H_4O$.An independent analysis gave a value of 132.16 for its molecular mass.What is the correct molecular formula ?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q29
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
An organic compound contains 49.30% carbon,6.84% hydrogen and its vapour density is 73.Molecular formula of compound is
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q28
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
A compound on analysis,was found to have the following composition :(i) Na=14.31% (ii) S=9.97% (iii) O=69.50% (iv) H=6.22%.Calculate the molecular formula of the compound assuming that whole of hydrogen in the compound is present as water of crystallization .Molecular mass of the compound is 322.
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q27
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
A carbon compound containing only carbon and oxygen has an approximate molecular mass of 290.On analysis,it is found to contain 50% by mass of each element .What is the molecular formula of the compound?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q26
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
A compound of carbon ,hydrogen and nitrogen contains these elements in the ratio 9 : 1 : 3.5.Calculate the empirical formula.If its molecular mass is 108,what is the molecular formula ?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q25
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
A compound contains 34.8% Oxygen,52.2% Carbon and 13.0% hydrogen .What is the empirical formula mass of the compound ?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q24
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
Calculate the empirical formula for a compound that contains 26.6% potassium,35.4% chromium and 38.1% oxygen.(Given :K=39.1,Cr=52,O=16)
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q23
medium
asked
Oct 24, 2013
by
sreemathi.v
1
answer
If $(1+\sqrt 2)^n=x_n+y_n\sqrt 2$, where $x_n,y_n$ are integers, then
jeemain
math
class11
ch8
binomial-theorem
positive-integral-index
medium
asked
Oct 23, 2013
by
rvidyagovindarajan_1
1
answer
The atomic composition of the entire universe is approximately given in the table below
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q22
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
A gas mixture contains 50% helium and 50% methane by volume .What is the percentage by mass of methane in the mixture
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q21
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
On analysis of an impure sample of sodium chloride,the percentage of chloride was found to be 45.5.What is the percentage of pure sodium chloride in the given sample ?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q20
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
Hydrogen and oxygen are combined in the ratio 1 : 16 by mass in hydrogen peroxide.Calculate the percentage of hydrogen and oxygen in hydrogen peroxide.
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q19
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
Calculate the percentage of nitrogen present in the composition of calcium nitrate.
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
percentage-composition
q18
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
The oxide of an element contains 32.33 percent of the element and the vapor density of its chloride is 79.Calculate the atomic mass of the element.
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q17
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
One gram of a chloride was found to contain 0.835g of chlorine.Its vapor density is 85.Calculate its molecular formula
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q16
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
On dissolving 2.0g of metal in sulphuric acid 4.51g of the metal sulphate was formed.The specific heat of the metal is 0.057cal/g.What is the exact atomic mass of the metal?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q15
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
A chloride of an element contains 49.5% chlorine.The specific heat of the element is $0.056$.Calcuate the equivalent mass,valency.
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q14
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
The equivalent weight of a metal is double than that of oxygen .How many times is the weight of its oxide greater than the weight of metal?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q13
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
The percentage of an element $m$ is 53 in its oxide of molecular formula $M_2O_3$.Its atomic mass is about
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q12
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
A metal m of equivalent mass E forms an oxide of molecular formula $M_xO_y$ .The atomic mass of the metal is given by the correct equation.
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q11
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
How many years it would take to spend one Avogadro's number of rupees at a rate of 10lakh of rupees in one second
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q10
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
The electric charge on the electron is $1.602\times 10^{-19}$ coulomb.How much charge is present on 0.1 mole of $Cu^{2+}$ ions?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
stoichiometry
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
How many electrons are present in 1.6g of methane?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q8
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
How many molecules of atoms of oxygen are present in 5.6 litres of oxygen $(O_2)$ at NTP?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q7
medium
asked
Oct 23, 2013
by
sreemathi.v
1
answer
The sum of the coefficients of integral powers of $x$ in the expansion of $(1+\sqrt x)^{40}$ is
jeemain
math
class11
ch8
binomial-theorem
positive-integral-index
medium
asked
Oct 22, 2013
by
rvidyagovindarajan_1
1
answer
From 200mg of $CO_2,10^{21}$ molecules are removed.How many moles of $CO_2$ are left?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q6
medium
asked
Oct 22, 2013
by
sreemathi.v
1
answer
The coefficient of the term independent of $x$ in the expansion of $\bigg[\large\frac{x+1}{x^{2/3}-x^{1/3}+1}-\frac{x-1}{x-\sqrt x}\bigg]^{\normalsize 10}$ is ?
jeemain
math
class11
ch8
binomial-theorem
general-and-middle-terms
medium
asked
Oct 22, 2013
by
rvidyagovindarajan_1
1
answer
What is the mass of $3.01\times 10^{22}$ molecules of ammonia?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q5
medium
asked
Oct 22, 2013
by
sreemathi.v
1
answer
How many molecules of water and oxygen atoms are present in 0.9g of water?
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q4
medium
asked
Oct 22, 2013
by
sreemathi.v
1
answer
Insulin contains 3.4% sulphur.Then the minimum molecular mass of the insulin is about
sat
chemistry
stoichiometry and the mole concept
jeemain
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
atomic-and-molecular-masses
q3
medium
asked
Oct 22, 2013
by
sreemathi.v
2
answers
A gas has a vapour density 11.2. The volume occupied by 1g of the gas at NTP is
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
stoichiometry
q2
medium
asked
Oct 22, 2013
by
sreemathi.v
1
answer
116 mg of a compound on vaporization in Victor mayer's apparatus displaces 44.8 ml of air measured at STP.The molecular mass of the compound is
jeemain
chemistry
physical-chemistry
class11
unit1
some-basic-concepts-in-chemistry
mole-concept-and-molar-masses
q1
medium
asked
Oct 22, 2013
by
sreemathi.v
1
answer
$\sum ^{n}_{r=0} r^2.\:^nC_r$ = ?
jeemain
math
class11
ch6
binomial-theorem
medium
asked
Oct 22, 2013
by
rvidyagovindarajan_1
1
answer
If $x\in R,$ then the value of $S=1-^nC_1.\large\frac{1+x}{1+nx}$$+^nC_2.\large\frac{1+2x}{(1+nx)^2}$$-^nC_3.\large\frac{1+3x}{(1+nx)^3}$$+..............(n+1) $terms = ?
jeemain
math
class11
ch8
binomial-theorem
properties-and-applications
medium
asked
Oct 21, 2013
by
rvidyagovindarajan_1
1
answer
If the sum of the coefficients of $1^{st},\:2^{nd}$ and $3^{rd}$ terms in the expansion of $(x^2+\large\frac{1}{x})$$^n $ is $46$, then the coefficient of the term independent of $x$ = ?
jeemain
math
class11
ch8
binomial-theorem
general-and-middle-terms
medium
asked
Oct 20, 2013
by
rvidyagovindarajan_1
1
answer
The sum of rational terms in the expansion of $(2^{\large\frac{1}{5}}$$+\sqrt 3)^{20}$ is
jeemain
math
class11
binomial-theorem
ch8
properties-and-applications
medium
asked
Oct 19, 2013
by
rvidyagovindarajan_1
1
answer
In a circle of diameter 50cm,the length of a chord is 25cm.Find the length of the minor arc of the chord.
jeemain
math
class11
ch3
trigonometric-functions
q49
angles
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
$\tan 5^{\large\circ}$ is a
jeemain
math
class11
ch3
trigonometric-functions
q48
basic-trigonometric-functions
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
If $\pi < \theta < \large\frac{3\pi}{2}$ the expression $\sqrt{4\sin^4\theta+\sin^22\theta}+4\cos^2\big(\large\frac{\pi}{4}-\frac{\theta}{2}\big)$ is equal to
jeemain
math
class11
ch3
trigonometric-functions
q47
trignometric-equations
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
If $p=\cos 55^{\large\circ},q=\cos 65^{\large\circ}$ and $r=\cos 175^{\large\circ}$ then the value of $\large\frac{1}{p}+\frac{1}{q}+\frac{r}{pq}$ is
jeemain
math
class11
ch3
trigonometric-functions
q46
angles
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
Evaluate : $\sin^{-1}\large\frac{4}{5}$$+\sin^{-1}\large\frac{5}{13}$$+\sin^{-1}\large\frac{16}{65}$
jeemain
math
class12
ch2
inverse-trigonometric-functions
q45
inverse-trignometric-properties
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
Find the value of $\tan\big[\large\frac{1}{2}$$\big(\sin^{-1}\large\frac{2x}{1+x^2}+$$\cos^{-1}\large\frac{1-y^2}{1+y^2}\big)\big],$$\mid x\mid < 1,y > 0$ and $xy <1$
jeemain
math
class12
ch2
inverse-trigonometric-functions
q44
inverse-trignometric-properties
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
Evaluate : $\tan\big[\large\frac{1}{2}$$\cos^{-1}\large\frac{\sqrt 5}{3}\big]$
jeemain
math
class12
ch2
inverse-trigonometric-functions
q43
inverse-trignometric-properties
medium
asked
Oct 17, 2013
by
sreemathi.v
1
answer
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