Law of constant proportions

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:

• Constant proportions

• Conservation of mass

• Multiple proportions

• Reciprocal proportions

What is the ratio of C:O in CO2?

• 4:8

• 3:7

• 8:4

• 2:4

The ratio of constituent elements in water from different sources are not always the same

• True

• False

2 elements C & D combines to form a compound CD. The same compound is obtained from different experiment. give the law in accordance to above observation

• law of conservation of mass

• law of constant proportion

• law of multiple proportion

Calculate the definite proportions for H₂O

• 11% of H and 89% of O

• 50% of H and 50% of O

• 20% of H and 80% of O

• 15% of H and 85% of O

1.A sample of NH₃ molecule irrespective of source contains 82.35% Nitrogen and 17.65% of Hydrogen by mass. This data supports:

• a) Law of Conservation of Mass

• b) Las of Multiple Proportions

• c) Law of Definite Proportions

• d) Avogadro’s Law

No matter how much extra oxygen is available, 12 grams of carbon always combines with 32 grams of oxygen. This best illustrates the Proust's law of:

• Multiple proportions

• Definite proportions

• Conservation of Energy

• Conservation of Mass

In a chemical reaction 150 g Baking soda mixture containing sodium bicarbonate and vinegar on heating gives 87 g of carbon dioxide gas. What mass of solid residue will left in food?

• 63 grams

• 65 grams

• 36 grams

• 87 grams

Who discovered the Law of Constant Composition, also known as the Law of Definite Proportions?

• John Dalton

• Joseph Proust

• Antoine Lavoisier

• Jons Jacob Berzelius

What is the ratio of hydrogen to oxygen by mass in pure water according to Proust's Law of Constant Proportion?

• 1:1

• 1:6

• 1:8

• 1:10