The answer is C
explanation
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: 100 times
Explanation: Since logaritms are about exponent of base ten.The concentration will be 10^2 or 100 times greater concentration.
The number of molecules of water is calculated as follows
find the moles of water= moles=mass/molar mass
moles = 69.1g/18 g/mol = 3.84 moles
by use of Avogadro law constant
that is 1 mole = 6.02 x10^23 molecules what about 3.84 moles of water
the molecules of water = (3.84 x 6.02 x10^23) = 2.312 x10^24 molecules
