The density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 g/cm3. What is that density in pounds per cubic inch? (1 in = 2.54 cm; 1 lb = 454 g)

0.492 lb/in^3

Explanation:

From Density of Mercury (13.6g/cm3) given,

Mass = 13.6g

Volume = 1cm3

Now we covert these variables as follows :

For Mass:

454 g = 1 lb

13.6g = 13.6/454 = 0.03lb

For volume:

2.54 cm = 1 in

1cm = 1/2.54 = 0.394in

Volume = (0.394in)^3 = 0.061 in^3

Density = Mass /volume

Density = 0.03lb/0.061 in^3

Density = 0.492 lb/in^3

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-