19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The number of water molecules is maximum in (NEET 2015)
If Avogadro number NA, is changed from 6.022 × 1023 mol–1 to 6.022 × 1020 mol–1, this would change (NEET 2015)
20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample ? (NEET 2015)
A mixture of gases contains H and O gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture ? (NEET 2015)
Which one of the following data has only four significant figures? (Kerala CEE 2014)
O Thus, 1.0 g Mg reactis with 0.67 . g O But only 0.56g O is available which less than 0.67 g is. Thus, O . is the limiting reagent. MOLE & EQUIVALENT CONCEPT Further, 16g O reacts with 24g of Mg. 0.56g O will re…
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. Mg = 24, O = 16) (NEET 2014)
When 22.4 litres of H2(g) is mixed with 11.2 litres of Cl2(g), each at STP, the moles of HCl(g) formed is equal to (NEET 2014)
Equal masses of H2, O2 and methane have been taken in a container of volume V at temperature 27°C in identical conditions. The ratio of the volumes of gases H2 : O2 : methane would be (NEET 2014)
6.02 × 1020 molecules of urea are present in 100 mL of its solution. The concentration of solution is (NEET 2013)
The vapour density of a gas is 11.2. The volume occupied by one gram of the gas at STP is (Manipal – 2013)
20.0 kg of N2(g) and 3.0 kg of H2(g) are mixed to produce NH3 (g). The amount of NH3(g) formed is (Kerala CEE 2011)
60g of a compound on analysis produced 24g of carbon, 4g hydrogen and 32g oxygen. The empirical formula of the compound is. (BVP 2010)
The number of atoms in 0.1 mol of a triatomic gas is ( A N =6.022×10 ) (CBSE AIPMT 2010)
How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl? (CBSE AIPMT 2008)
Number of atoms of He in 100 u of He (atomic weight of He is 4) are (BCECE 2008)
The maximum number of molecules are present in (BCECE 2008)
Mass of 0.1 mole of methane is (KCET 2008)
An element, X has the following isotopic composition: 200X : 90% 199X : 8.0% 202X : 2.0% The weighted average atomic mass of the naturally occurring element X is closest to (AIPMT 2007)
The crystalline salt Na2SO4.xH2O on heating loses 55.9% of its weight. The formula of crystalline salt is (Kerala CEE 2007)
Gram molecular volume of oxygen at STP is (KCET 2007)
The number of gram molecules of chlorine in 6.02×1025 hydrogen chloride molecule is (KCET 2007)
25 g of MCl4 contains 0.5 mole chlorine then its molecular weight is (Punjab PMET 2007)
The weight of one molecule of a compound C60H122 is (BHU 2007)
5.6 g of a metal forms 12.7 g of metal chloride. Hence equivalent weight of the metal is