## Some Basic Concepts of Chemistry

### Chemistry

#### Previous Years Questions

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An organic compound contains 78% (by wt.) carbon and remaining percentage of hydrogen. The right option for the empirica...
NEET 2021
The number of protons, neutrons and electrons in 17571Lu, respectively, are :
NEET 2020 Phase 1
Which one of the following has maximum number of atoms?
NEET 2020 Phase 1
The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber’s process is :
NEET 2019
In which case is number of molecules of water maximum?
NEET 2018
A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. H2SO4 . The evolved gaseous mixture is passed...
NEET 2018
Which of the following is dependent on temperature?
NEET 2017
Suppose the elements X and Y combine to form two compounds XY2 and X3Y2. When 0.1 mole of XY2 weights 10 g and 0.05 mole...
NEET 2016 Phase 2
A mixture of gases contains H2 and O2 gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the...
AIPMT 2015 Cancelled Paper
The number of water molecules is maximum in
AIPMT 2015
If Avogadro number NA, is changed from 6.022 $$\times$$ 1023 mol$$-$$1 to 6.022 $$\times$$ 1020 mol$$-$$1, this woul...
AIPMT 2015
What is the mass of the precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solut...
AIPMT 2015
1.0 g of magnesium is burnt with 0.56 g O2 in a closed vessel, Which reactant is left in excess and how much ? (At. wt. ...
AIPMT 2014
When 22.4 liters of H2(g) is mixed with 11.2 litres of Cl2(g), each at S.T.P. the moles of HCl(g) formed is equal to ...
AIPMT 2014
Equal masses of H2, O2 and methane have been taken in a container of volume V at temperature 27oC in identical condition...
AIPMT 2014
In an experiment it showed that 10 mL of 0.05 M solution of chloride required 10 mL of 0.1 M solution of AgNO3, which of...
NEET 2013 (Karnataka)
6.02 $$\times$$ 1020 molecules of urea present in 100 mL of its solution. The concentration of solution is
NEET 2013
Which has the maximum number of molecules among the following ?
AIPMT 2011 Mains
25.3 g of sodium carbonate, Na2CO3 is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissocia...
AIPMT 2010 Prelims
The number of atoms in 0.1 mol of a triatomic gas is (NA = 6.02 $$\times$$ 1023 mol$$-$$1)...
AIPMT 2010 Prelims
10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reacti...
AIPMT 2009
An organic compound contains carbon, hydrogen and oxygen. Its elemental analysis gave C, 38.71% and H, 9.67%. The empiri...
AIPMT 2008
How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g HCl ?
AIPMT 2008
What volume of oxygen gas (O2) measuread at 0oC and 1 atm, is needed to burn completely 1 L of propane gas (C3H8) measu...
AIPMT 2008
An element, X has the following isotopic composition: 200X : 90%&nbsp;&nbsp;199X : 8.0%&nbsp;&nbsp;202X : 2.0% The weig...
AIPMT 2007
The maximum number of molecules is present in
AIPMT 2004
The percentage of C, H and N in an organic compound are 40%, 13.3% and 46.7% respectively then empirical formula is
AIPMT 2002
Which has maximum molecules?
AIPMT 2002
Specific volume of cylinfrical virus particle is 6.02 $$\times$$ 10$$-$$2 cc/g whose radius and length are 7 $$\mathop... AIPMT 2001 Molarity of liquid HCl, if density of solution is 1.17 g/ce is AIPMT 2001 Percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (at. wt. = 78.4) then minimum molecular weight of pero... AIPMT 2001 Oxidation numbers of A, B, C are + 2, +5 and$$-2 respectively. Possible formula of compound is
AIPMT 2000
Volume of CO2 obtained by the complete decomposition of 9.85 g of BaCO3 is
AIPMT 2000
In quantitative analysis of second group in laboratory, H2S gas is passed in acidic medium for precipitation. When Cu2+ ...
AIPMT 2000