Two samples of sodium chloride were decomposed into their constituent elements. One sample produced 2.84 g of sodium and 4.37 g of chlorine. Which of the following could be the results of the decomposition of the other sample, being consistent with the law of constant composition (also called the law of definite proportions or law of definite composition)? a) 4.17 g of sodium and 3.75 g of chlorine
b) 4.17 g of sodium and 6.42 g of chlorine
c) 4.17 g of sodium and 1.05 g of chlorine
d) 4.17 g of sodium and 12.1 g of chlorine

The correct answer is b) 4.17 g of sodium and 6.42 g of chlorine

Explanation:

According to the law of definite proportions a chemical compound is composed always by the same elements in the same proportions by mass. In this case, the proportion of the elements by mass will be 4.37 g of chlorine (Cl) per 2.84 g of sodium (Na):

4.37 Cl/2.84 g Na= 1.54

We can calculate the proportions of the results in order to see which is the correct:

a) 3.75 g Cl/4.17 g Na = 0.899

b) 6.42 g Cl/4.17 g Na = 1.539 ⇒ ≅1.54

c) 1.05 g Cl/4.17 g Na = 3.971

d) 12.1 g Cl/4.17 g Na = 2.901

The option in which the proportion Cl/Na is equal to 1.54 is option b

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.