EASY
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The relative number and the kind of atoms in a given compound are constant. This postulate of Dalton's atomic theory can explain the law of .

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Important Questions on Atoms and Molecules

MEDIUM

The reaction of the burning of carbon in oxygen is represented by equation

C(s)+O2(g)  CO2(g)+Heat+Light

When 9.0 g of solid carbon is burnt in 16.0 g of oxygen gas the mass of carbon dioxide gas formed would be:

(Note: Atomic mass of C-12,o u, O=16.0 u)

 

 

MEDIUM
Two samples A and B of a pure substance containing elements Y and Z are obtained from two different sources. 5g of sample A contains 1.25g of Z. Sample B is made of 75% of Y by weight. This is an illustration of which of the following laws?
MEDIUM
How will you show that there is no change in mass during a chemical reaction?
MEDIUM
In a reaction, 10 g of calcium carbonate reacts with 7.3 g of hydrochloric acid. The products of reaction are 11.1 g of calcium chloride, 1.8 g of water and 4.4 g of carbon dioxide gas. Show that these observations are in agreement with the law of conservation of mass.
EASY
State the law of constant proportions.
EASY
According to the law of conservation of mass, the mass of the products is equal to the mass of the reactants.
MEDIUM
Law of conservation of mass holds true and can be verified in a school laboratory
EASY
"The matter (mass) can neither be created nor be destroyed in a chemical reaction." This statement is:
EASY
Law of conservation of mass was attributed by:
EASY
In a chemical compound, the constituent elements are present in definite proportion by mass.
EASY
State the law of conservation of mass.
HARD
State and explain the law of constant proportions by giving an example.
MEDIUM
What do you understand by the law of constant proportions? Illustrate it with two examples.
MEDIUM
In an experiment, 9.6 g of sulphur bums completely in 9.6 g of oxygen to produce 19.2 g of sulphur dioxide. In another experiment, 9.6 g of sulphur is made to bum completely in 100 g of oxygen. What mass of sulphur dioxide is formed. Which law of chemical combination governs your answer?
EASY
The law of constant proportion requires the combining elements to react only in simple mass ratio.
MEDIUM
Magnesium and oxygen combine in the ratio of 3:2 by mass to form magnesium oxide. How much mass of oxygen is required to react completely with 12 g of magnesium?
MEDIUM
State law of constant proportions.
EASY
State the law of conservation of mass.
EASY
Theory of constant composition was proposed by:
MEDIUM

Select from the following figure(s) that correctly represent(s) the experimental set-up for the verification of conservation of mass in a chemical reaction.
BaCl2(aq)+Na2SO4(aq)BaSO4(s)+2NaCl(aq)

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