19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
An organic compound contains 78% (by wt.) carbon and remaining percentage of hydrogen. The right option for the empirical formula of this compound is: [Atomic wt. of C is 12, H is 1] (NEET 2021)
Which one of the following has maximum number of atoms? (NEET 2020)
The density of 2 M aqueous solution of NaOH is 1.28 g/cm3. The molality of the solution is [Given that molecular mass of NaOH = 40 g mol–1] (Odisha NEET 2019)
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)
Which of the following is dependent on temperature? (NEET 2017)
Suppose elements X and Y combine to form two compounds XY2 and X3Y2. When 0.1 mol of XY2 weighs 10g and 0.05 mol of X3Y2 weighs 9g, the atomic weights of X and Y are (NEET 2016)
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 solution? (Ag = 107.8, N = 14, O = 16, Na = 23, Cl = 35.5) (NEET 2015)
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)
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)
A mixture of CaCl2 and NaCl weighing 4.44 g is treated with sodium carbonate to precipitate all the Ca2+ ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get 0.56 g of CaO. The percen…
Volume of a gas at NTP is 1.12×10–7 cm3. The number of molecules in it is (Manipal 2010)
1.520 g of hydroxide of a metal on ignition gave 0.995 g of oxide. The equivalent weight of metal is (JCECE 2008)
A metal M of equivalent mass E forms an oxide of molecular formula MxOy. The atomic mass of the metals is given by the correct equation (BCECE 2008)