Answer:
Precipitation will occur after the concentration of fluoride ions exceeds 0.01 M.
4 mL volume of NaF must be added to cause
to precipitate.
Explanation:
Concentration of barium ions = ![[Ba^{2+}]=0.016 M](https://tex.z-dn.net/?f=%5BBa%5E%7B2%2B%7D%5D%3D0.016%20M)
Volume of barium ion solution = 2.0 L

The solubility product of the barium fluoride = 
![K_{sp}=[Ba^{2+}][F^-]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BBa%5E%7B2%2B%7D%5D%5BF%5E-%5D%5E2)
![1.6\times 10^{-6}=[0.016 M]\times [F^-]^2](https://tex.z-dn.net/?f=1.6%5Ctimes%2010%5E%7B-6%7D%3D%5B0.016%20M%5D%5Ctimes%20%5BF%5E-%5D%5E2)
![[F^-]=0.01 M](https://tex.z-dn.net/?f=%5BF%5E-%5D%3D0.01%20M)
Precipitation will occur after the concentration of fluoride ions exceeds 0.01 M.
Concentration of fluoride ion = 
Volume of solution = 
Concentration of NaF solution added = 
Volume of NaF solution added = 


1 L = 1000 mL
0.004 L = 0.004 × 1000 mL = 4 mL
4 mL volume of NaF must be added to cause
to precipitate.
Answer:
Formaldehyde is highly soluble in water.
Explanation:
Formaldehyde is the simplest of the aldehydes (R−CHO) it is an organic compound which occurs naturally with the formula H−CHO. . The IUPAC name of formaldehyde is methanal.
Formaldehyde at room temperature is a colorless gas and the liquid is invisible or like white-water. Formaldehyde has an irritating and very pungent like odour. Formaldehyde is very soluble in water.
Now according to Henry's constant law (3 × 10-5 kPa·m3/mol) Formaldehyde will be very unlikely to volatilize from water.and hence, Formaldehyde is considered to be highly soluble in water.
Answer:
Mass = 713.4 ×10⁻⁴ g
Explanation:
Given data:
Number of moles of calcium phosphate = 2.3×10⁻⁴ mol
Mass of calcium phosphate = ?
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of calcium phosphate is 310.18 g/mol
by putting values,
2.3×10⁻⁴ mol = mass / 310.18 g/mol
Mass = 2.3×10⁻⁴ mol × 310.18 g/mol
Mass = 713.4 ×10⁻⁴ g
Answer: No hydrogen bond cannot occur in this alpha helix structure.
Explanation: For hydrogen bond to form, the electronegativity difference should be more than 1.7. carbon has an electronegativity of 2.5 whereas hydrogen has 2.1 so their electronegativity difference is 0.3. So in this alpha helix structure cannot occur.