Answer:
a) CaF₂.
b) 7.81g of CaF₂ are present.
Explanation:
a) The calcium ion has as charge Ca²⁺ and fluoride ion is F⁻, that means formula unit is:
CaF₂
b) 1 molecule of CaF₂ contains 2 anions, F⁻. Thus, the moles of CaF₂ is:
1.2x10²³ anions * (1 moleculeCaF₂ / 2 anions) = 6x10²² molecules of CaF₂
6.022x10²³ molecules = 1mol:
6x10²² molecules of CaF₂ * (1mol / 6.022x10²³molecules) = 0.10 moles CaF₂.
1 mole of CaF₂ has a mass of 78.07g:
0.10 moles CaF₂ * (78.07g / mol) =
7.81g of CaF₂ are present
Answer:
Matter is the term for any type of material. Matter is anything that has mass and takes up space. At a minimum, matter requires at least one subatomic particle, although most matter consists of atoms.
Some examples are: Water, books, pencils, sun, earth, moon, electron, proton, mesons, and quarks
Answer:
The [OH⁻] of a solution that has a pOH of 2.7 will be 2*10⁻³
Explanation:
The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution.
pOH indicates the concentration of hydroxyl ions [OH-] present in a solution. In this way, pOH is defined as the negative logarithm of the activity of hydroxide ions, that is, the concentration of OH- ions:
pOH= -log [OH⁻]
In this case, pOH has a value of 2.7. Replacing:
2.7= -log [OH⁻]
and solving:
[OH⁻]=10⁻² ⁷
you get:
[OH⁻]≅ 2*10⁻³
<u><em>The [OH⁻] of a solution that has a pOH of 2.7 will be 2*10⁻³</em></u>
