Ms. Terries was given a beautiful deep red gem. She knew she might be holding a ruby. Or, she might be holding a stone worth more than rubies, a stone rared than diamonds – a red beryl. Ms. Terries needed to be careful in her calculations. Red Beryl is a mixture of minerals and its density can be anywhere from 2.63g/cm3 to 2.92 g/cm3 Rubies can also vary in density from 3.9 g/cm3 to 4.1 g/cm3. Ms. Terries weighed the stone. It weighed 4.35 g. When put into a graduated cylinder of water, the water level rose 1.5 mL. Determine the density of the gem. Was it ruby or red beryl?

red beryl

Explanation:

Red Beryls = Density range is 2.63g/cm3 to 2.92 g/cm3

Rubies = Density Range is 3.9 g/cm3 to 4.1 g/cm3

Mass of stone = 4.35 g

Volume of solid = change in water level = 1.5 mL = 1 cm3

Relationship between mass, volume and density is given by;

Density = Mass / Volume

Density = 4.35 / 1.5 = 2.9 g/cm3

The density of the stone falls in the red beryls range hence it is a red beryl.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.