19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The number of molecules in 4.25 g of ammonia is about
The law of conservation of mass holds good for all of the following except:
3 g of a hydrocarbon on combustion in excess of oxygen produces 8.8g of CO2 and 5.4 g of H2O. The data illustrates the law of:
Zinc sulphate contains 22.65% Zn and 43.9% H2O. If the law of constant proportions is true, then the mass of zinc required to give 40g crystals will be :
If water sample are taken from sea, rivers or lake, they will be found to contain hydrogen and oxygen in the approximate ratio of 1:8. This indicates the law of:
A sample of CaCO3 has Ca = 40%, C = 12% and O = 48%. If the law of constant proportions is true, then the mass of Ca in 5 g of CaCO3 from another source will be :
n g of substance X reacts with m g of substance Y to form p g of substance R and q g of substance S. This reaction can be represented as follows : X + Y = R + S The relation which can be established in the amounts of…
In 1811, Avogadro proposed that equal volumes of gases at the same …A… and …B… should contain equal number of molecules. Here, A and B refer to
The Gay Lussac’s law was explained properly by the work of …A… in 1811. Here, A refers to
Which law states that if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of other element, are in the ratio of small whole number?
Which law states that matter can neither be created nor destroyed?
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 …
…A… are formed when atoms of different elements combine in a …B… ratio. Here, A and B refer to
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.
Which of the following has the largest volume ?
How many significant figures does 63180 have?
Number of atoms in 560g of Fe (atomic mass 56 g mol–1) is
If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will
P and Q are two elements which forms P2Q3 and PQ2. If 0.15 mole of P2Q3 weights 15.9g and 0.15 mole of PQ2 weights 9.3g, the atomic weight of P and Q is (respectively) :
100 mL of mixture of NaOH and Na2SO4 is neutralised by 10 mL of 0.5 M H2SO4. Hence, NaOH in 100 mL solution is
In one molal solution that contains 0.5 mole of a solute, there is (NEET 2022)
The total number of electrons present in 18 ml of water (density of water is 1 g ml–1) is
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)