Answer:
sun and ocean. I had this last week
Answer:
1.41x10⁻⁴ M
It will not attain the level recommended.
Explanation:
When the NaF is added to the water, it will dissociate, forming the ions Na⁺ and F⁻. The fluoride ion may react with the Ca⁺² ions to form the salt CaF₂, which can dissociate too. The dissociation, or solubilization, is characterized by the solubility product (Kps), which is an equilibrium constant. For CaF₂, Kps = 4.0x10⁻¹¹, so:
CaF₂(s) ⇄ Ca⁺² + 2F⁻(aq)
The solids are not put in the equilibrium expression, so:
Kps = [Ca⁺²] * [F⁻]²
4.0x10⁻¹¹ = 0.0020*[F⁻]²
[F⁻]² = 2.0x10⁻⁸
[F⁻] = √2.0x10⁻⁸
[F⁻] = 1.41x10⁻⁴ M
Which is the maximum concentration to the solution be saturated, after that, the solid will precipitated. Because the concentration of fluoride ion is lower than the recommended, it will not attain.
Answer:
25.9 g
Explanation:
Given that,
No of moles of calcium phosphate, ![n=9.3\times 10^{-2}](https://tex.z-dn.net/?f=n%3D9.3%5Ctimes%2010%5E%7B-2%7D)
We need to find how many grams of calcium phosphate has this much of no of moles.
Mass divided by molar mass is equal to the no of moles on a molecule.
The molar mass of calcium phosphate is 310.18 g/mol
Using the concept of no of moles as follows :
![n=\dfrac{m}{M}\\\\m=n\times M\\\\m=9.3\times 10^{-2}\times 310.18\\\\m=28.84\ g](https://tex.z-dn.net/?f=n%3D%5Cdfrac%7Bm%7D%7BM%7D%5C%5C%5C%5Cm%3Dn%5Ctimes%20M%5C%5C%5C%5Cm%3D9.3%5Ctimes%2010%5E%7B-2%7D%5Ctimes%20310.18%5C%5C%5C%5Cm%3D28.84%5C%20g)
Out of given options, option (a) i.e. 25.9 g is the correct answer.
Answer:
Ans: 5.8g
Explanation:
31.35L * 1mol/22.4L * 4.00g/1mol = 5.81g
"Melting Point" - The Required <span>amount of heat to melt a substance</span>