Liquids and solids are left out of the equilibrium constant expression because their concentrations remain constant during reactions. what is the molarity concentration of liquid water at 25.0 latex: ^\circ ∘c given that its density is 0.997 g/ml at that temperature?
a.23.5 m
b.0.997 m
c.0.180 m
d.0.156 m
e.55.3 m

55.3 M

Explanation:

Given temperature = 25°C

Density = 0.997 g/mL

Based on density the mass of water per L = 997 grams

The molar mass of water = 18

The moles of water =

The molarity is defined as the moles of water per litre.

The moles = 55.3

Volume = 1 L

So molarity = 55.3 /1 = 55.3 M

  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-