G10 Unit 26 Fundamental Laws of Chemical Reaction

Question 1

a French chemist, first put forth the law of definite composition

Answer 1

Joseph Louis Proust

Question 2

states that the elemental composition of a pure compound is always the same

As long as it is a pure compound, a teaspoon of this compound will have the same elemental percentage composition as a kilogram of each compound.

Answer 2

law of definite composition

Question 3

states that there are compounds which are made up of the same elements but of varying whole number ratios

Carbon and oxygen can combine in a 1:1 ratio to form carbon monoxide or 1:2 ratio to form carbon dioxide.
In the same manner, hydrogen and oxygen can combine in 2:1 ratio to form water or 2:2 ratio to form hydrogen peroxide.

Answer 3

law of multiple proportions

Question 4

law of multiple proportions, which was put forth by English scientist

Answer 4

John Dalton

Question 5

ratio depends on the initial reactants present in the surroundings as well as environmental conditions

For instance, carbon dioxide is produced if carbon is made to react with excess oxygen gas. When oxygen gas is limited, carbon monoxide is produced

Answer 5

Law of Multiple Proportions

Question 6

relates the proportions of elements that have the ability to combine to different elements

By knowing the proportions of elements present in two compounds that have a “common element”, the proportion of the “variable elements” with respect to one another can easily be calculated.

This law gives birth to more complex yet systematic calculations found in stoichiometry.

Answer 6

Law of Reciprocal Proportions

Question 7

Putting everything in symbols, consider compounds AB and BC, where A and C are the variable elements while B is the common element.

The law states that if you calculate the mass ratio for compound AB and BC you will be able to calculate for the mass ratio A:C in the compound AC by simple stoichiometry.

For NaCl and HCl, the ratio of Na:H can be determined as

Answer 7

Law of Reciprocal Proportions

Question 8

also known as the father of modern chemistry, proposed the law of conservation of mass

Answer 8

Antoine Lavoisier

Question 9

states that the there is no observable change in the quantity of matter undergoing a physical or chemical change.

This means that for a chemical reaction, the total mass of reactants will be equal to the total mass of the products.

Answer 9

law of conservation of mass