Answer:
Density = 8.92 g/cm³
Explanation:
Density shows the relation of the mass and volume of a determined object. We have this deffinition:
Density = mass / volume
First of all, we calcualte the volume of the block of copper metal, with the data given:
8.4 cm . 5.5 cm . 4.6 cm = 212.52 cm³
Now we replace at the density formula:
Density = 1896 g /212.52 cm³ = 8.92 g/cm³
3.16 X 10^-11 M is the [OH-] concentration when H3O+ = 1.40 *10^-4 M.
Explanation:
data given:
H30+= 1.40 X 10^-4 M\
Henderson Hasslebalch equation to calculate pH=
pH = -log10(H30+)
putting the values in the equation:
pH = -log 10(1.40 X 10^-4 M)
pH = 3.85
pH + pOH =14
pOH = 14 - 3.85
pOH = 10.15
The OH- concentration from the pOH by the equation:
pOH = -log10[OH-]
10.5= -log10[OH-]
[OH-] = 10^-10.5
[OH-] = 3.16 X 10^-11 is the concentration of OH ions when hydronium ion concentration is 1.40 *10^-4 M.
The focal length, like you said it's the distance between the FOCAL point and the mirror.
Hope this helps.... :)
