19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
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 …
The law of conservation of mass holds good for all of the following except:
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:
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
Who proposed Law of Conservation of Mass?
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 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 …
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.
The result of the operation 2.5 × 1.5 should be which of the following on the basis of significant figures?
2.005 has ….A…. significant figures. Here, A refers to
How can we write 232.508 in scientific notation?
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?
Assertion :Number of molecules present in SO₂ is twice the number of molecules present in O₂. Reason : Molecular mass of SO₂ is double to that of O₂.
How many significant figures are present in 0.10100 × 103?
Which of the following is the most accurate measurement?