Consider a voltaic cell where the anode half-reaction is zn(s) → zn2+(aq) + 2 e− and the cathode half-reaction is sn2+(aq) + 2 e– → sn(s). what is the concentration of sn2+ if zn2+ is 2.5 × 10−3 m and the cell emf is 0.660 v? the standard reduction potentials are given below zn+2(aq) + 2 e− sn2+(aq) + 2 e– →→ zn(s) sn(s) e∘red e∘red == −0.76 v −0.136 v consider a voltaic cell where the anode half-reaction is and the cathode half-reaction is . what is the concentration of if is and the cell emf is 0.660 ? the standard reduction potentials are given below
a. 7.6 × 10−3 m
b. 9.0 × 10−3 m
c. 1.9 × 10−4 m
d. 6.9 × 10−4 m
e. 3.3 × 10−2 m

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.