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:
0.7692 M ≅ 0.77 M.
Explanation:
- It is known that the no. of millimoles of a solution before dilution is equal to the no. of millimoles of the solution after the dilution.
<em>(MV) before dilution = (MV) after dilution.</em>
M before dilution = 2.0 M, V before dilution = 0.25 L.
M after dilution = ??? M, V after dilution = 0.25 L + 0.40 L = 0.65 L.
∴<em> M after dilution = (MV) before dilution/(V) after dilution</em> = (2.0 M)(0.25 L)/(0.65 L) =<em> 0.7692 M ≅ 0.77 M.</em>
Fluorine and Nitrogen are both non-metals which posses non polar covalent bonds. So in this case, only KCl has polar covalent bond.
Before solving, let us understand the meaning of covalent and ionic bonds and how to identify them.
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
Therefore, the polar covalent bond is shown by KCl as it shows sharing of equal electrons amongst them.
To learn more about bonds, refer: brainly.com/question/28295504
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The question is missing. Here is the complete question.
One light beam has wavelength, , and frequency, f₁. Another light beam has wavelength, , and frequency, f₂. Write a proportion that shows how the ratio of the wavelengths of these two light beams is related to the ratio of the frequencies.
Answer:
Explanation: In vacuum, eletromagnetic waves travels at a constant speed called "speed of light", whose symbol is [c] and magnitude is 3x10⁸m/s.
Speed of light, frequency and wavelength are related by the formula:
So, if one light beam has wavelength and frequency, and f₁, respectively, the second beam has wavelength and frequency f₂ and both travel at speed of light:
Then, the ratio that shows the relation between frequencies and wavelengths of these light beams is
N= number of molecules
n= 2.3x10^23/6.022x10^23
= 0.381 mol
Now,
M= molar mass in g/mol
m= mass in grams
m=nxM
=0.381 molx137 g/mol
= 52.197g
So, the correct answer should be C