19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
What did Dalton’s Theory couldn’t explain?
Which of the following statement is false? (I) Matter consists of indivisible atoms. (II) All the atoms of a given element have identical properties including identical mass. (III) Compounds are formed when atoms of …
Assertion :Density is expressed as g mL–1 whereas specific gravity is dimension less. Reason :Specific gravity is ratio of the masses of solution and solvent.
How many significant figures does 63180 have?
_________is referred to as the closeness of different measurements for the same quantity.
How many significant figures are present in 0.10100 × 103?
Which of the following is the most accurate measurement?
The result of the operation 2.5 × 1.5 should be which of the following on the basis of significant figures?
Which of the following represents the largest unit?
Which of the following statements(s) is false about the arrangement of particles, in different states of matter?
2.005 has ….A…. significant figures. Here, A refers to
How can we write 232.508 in scientific notation?
What mass of 95% pure CaCO₃ will be required to neutralise 50 mL of 0.5 M HCl solution according to the following reaction? CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + CO₂(g) + 2H₂O(l) [Calculate upto second place of decimal po…
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)
In which case is number of molecules of water maximum? (NEET 2018)
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)
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)
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 react w…
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)
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)