We make a graphic of this problem to define the angle.
The angle we can calculate through triangle relation, that is,
With this function we should only calculate the derivate in function of c
That is the rate of change of 
.
b) At this point we need only make a substitution of 0 for c in the equation previously found.
Hence we have finally the rate of change when c=0.
The volume of the block of wood is given by length × width ×height
= 2.75 × 4.80 × 7.5
= 99 cm³
Density is given by mass/volume
Thus = 84.0 g/ 99 cm³
= 0.848 g/cm³
Hence; since the block is less dense than water (1 g/cm³) it will float
<h3><u>Answer;</u></h3>
= 0.0000001 mol/L
= 0.0000001 mol/L
= 1:1
<h3><u>Explanation;</u></h3>
What is the concentration of H+ ions at a pH = 7?
The formula for ph is given by:
pH=−log10[H+]
In calculating for the concentration of hydrogen ion, the formula is given by:
[H+]=(10)^(-pH)
Therefore; at pH = 7
[H+]=(10)^(-7)
<u>= 0.0000001 mol/L </u>
What is the concentration of OH– ions at a pH = 7?
pH+pOH=14
7+pOH=14
pOH= 7
[OH-]=(10)^(-pOH)
[OH-]=(10)^(-7)
<u>= 0.0000001 mol/L </u>
What is the ratio of H+ ions to OH– ions at a pH = 7?
1:1
