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Questions >> JEEMAIN and NEET >> Chemistry

Chemistry

In compound $C,H,N$ atoms are present in 9 : 1 : 35 by weight .Molecular weight of compound is 108.It molecular formula is

asked Oct 28, 2013 by sreemathi.v

1 answer

Which of the following changes with increases in temperature?

asked Oct 28, 2013 by sreemathi.v

1 answer

Number of atoms in 558.5g $Fe$ (at.wt =55.85) is

asked Oct 28, 2013 by sreemathi.v

1 answer

One litre of $CO_2$ is passed over hot cake.The volume becomes 1.4litre.The percent composition of products is

asked Oct 28, 2013 by sreemathi.v

1 answer

On repeated sparking 10ml of mixture of carbon monoxide and nitrogen required 7ml of oxygen for combustion of CO and $N_2$ to $CO_2$ and NO.The volume of nitrogen in mixture is (all volumes are measured under identical conditions).

asked Oct 28, 2013 by sreemathi.v

1 answer

20ml of 0.1m $H_3BO_3$ solution on complete neutralization requires __________ml of 0.05m $NaOH$ solution

asked Oct 28, 2013 by sreemathi.v

1 answer

One mole of potassium chlorate is thermally decomposed excess of aluminum is burnt in the gaseous product .How many mole of aluminum oxide are formed?

asked Oct 28, 2013 by sreemathi.v

1 answer

If half mole of oxygen combine with Al to form $Al_2O_3$,the weight of Al used in the reaction is

asked Oct 25, 2013 by sreemathi.v

1 answer

When the same amount of zinc is treated separately with excess of $H_2SO_4$ and excess of $NaOH$,the ratio of volumes of $H_2$ evolved is

asked Oct 25, 2013 by sreemathi.v

1 answer

Number of ions present in 2.0 litre of a solution of $0.8MK_4Fe(CN)_6$ is

asked Oct 25, 2013 by sreemathi.v

1 answer

The mole fraction of water in 20% aqueous solution of $H_2O_2$ is :

asked Oct 25, 2013 by sreemathi.v

1 answer

A partially dried clay mineral contains 8% water.The original sample contained 12% water and 45% silica.The % of silica in the partially dried sample in nearly :

asked Oct 25, 2013 by sreemathi.v

1 answer

The percentage of sodium in a break-fast cereal,labelled as 110mg of sodium per 100g of cereal is

asked Oct 25, 2013 by sreemathi.v

1 answer

The solubility of $K_2SO_4$ in water is 16g at $50^{\large \circ}C$.The minimum amount of water required to dissolve $4g\;K_2SO_4$ is

asked Oct 25, 2013 by sreemathi.v

1 answer

$Al_2(SO_4)_3.XH_2O$ has 8.1% aluminum by mass.The value of $X$ is

asked Oct 25, 2013 by sreemathi.v

1 answer

The hydrated salt,$Na_2SO_4.nH_2O$ undergoes 55.9% loss in weight on heating and becomes anhydrous.The value of n will be

asked Oct 25, 2013 by sreemathi.v

1 answer

In nature,abundance of $^1H_1$ and $^2H_1$ are 99.985 and 0.015 percent respectively and water obtained from it contains $H_2O$ and $D_2O$.The number of $D_2O$ molecules in 400mL water (if density is assumed to be 1.0g/mL) will be :

asked Oct 25, 2013 by sreemathi.v

1 answer

Haemoglobin $(C_{2952}H_{9664}N_{812}O_{832}S_8Fe_4)$ is oxygen carrier. If a person has $5L$ blood and each mL of blood has $5\times 10^9$ R.B.C and each R.B.C has $2.8\times 10^8$ haemoglobin molecules, then how many grams of haemoglobin is present in the body of that person?

asked Oct 25, 2013 by sreemathi.v

1 answer

A silicon (atomic weight=28) chip used in an integrated circuit of a microcomputer has a mass of 5.68 mg. How many silicon (Si) atoms are present in this chip.

asked Oct 25, 2013 by sreemathi.v

1 answer

In the first world war ,$1.1\times 10^8$kg of position gas were fired on the allied forces.If the gas is assumed to be phosgene,how many molecules of the gas correspond to the amount fired on allied forces.

asked Oct 25, 2013 by sreemathi.v

1 answer

$\large\frac{2}{3}$ of the atoms in water molecule are hydrogen .What % weight of a water molecule is the weight of 2 hydrogen atoms:

asked Oct 25, 2013 by sreemathi.v

1 answer

16g $SO_x$ occupies 5.6 litres at STP. Assuming the nature of the gas to be ideal, the value of $x$ is

asked Oct 25, 2013 by sreemathi.v

1 answer

Chlorophyll,a green coloring matter contains 2.68% mg.The number of atoms of mg present 1g chlorophyll are

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

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

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

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

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

asked Oct 24, 2013 by sreemathi.v

1 answer

An organic compound containing C and it has 92.3% carbon .Its empirical formula is :

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 ?

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

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.

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?

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 ?

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 ?

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)

asked Oct 24, 2013 by sreemathi.v

1 answer

The atomic composition of the entire universe is approximately given in the table below

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

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 ?

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.

asked Oct 23, 2013 by sreemathi.v

1 answer

Calculate the percentage of nitrogen present in the composition of calcium nitrate.

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.

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

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?

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.

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?

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

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.

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

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?

asked Oct 23, 2013 by sreemathi.v

1 answer

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