19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
‘amu’ has been replaced by ‘u’ which is known as …A… Here, A refers to
When a hydrate of Na2CO3 is heated until all the water is removed, it loses 54.3 per cent of its mass. The formula of the hydrate is
Statement I: The constituents of a compound can be separated into simpler substances by physical method. Statement II: The constituents of compound can be separated by chemical method. Choose the correct …
Consider the following statements, (I) Mixture may contain the components in any ratio and their composition is variable. (II) Pure substances have fixed composition. (III) The constituents of pure substanc…
Assertion :Pure water obtained from different states of India always contains hydrogen and oxygen in the ratio of 1 : 8 by mass. Reason: Total mass of reactants and products during chemical change is always the …
A sample of calcium carbonate (CaCO3) has the following percentage composition: Ca = 40%, C = 12%, O = 48%. If the law of constant proportions is true, then the weight of calcium in 4g of a s…
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…
Hydrogen and oxygen combine to form H2O2 and H2O containing 5.93% and 11.2% hydrogen respectively. The data illustrates:
The percentage of copper and oxygen in samples of CuO obtained by different methods were found to be the same. This illustrates the law of
The law of multiple proportion is illustrated by
Carbon and oxygen combine to form two oxides, carbon monoxide and carbon dioxide in which the ratio of the weights of carbon and oxygen is respectively 12:16 an 12:32. These figures illustrate the:
Which of the following reaction is not according to the law of conservation of mass
Who proposed Law of Conservation of Mass?
If 6.3g of NaHCO3 are added 15.0g CH3COOH solution, the residue is found to weigh 18.0 g. What is the mass of CO2 released in the reaction?
One of the statements of Dalton’s atomic theory in given below “Compounds are formed when atoms of different elements combine in a fixed ratio” Which of the following laws is not related to this…
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?