Answer:
The molar mass in g/mol is 121.4 g/m
Explanation:
Let's apply the Ideal Gases Law to solve this:
P . V = n . R. T
V = 125 mL → 0.125L
P = 754 Torr
760 Torr ___ 1 atm
754 Torr ____ (754 / 760) = 0.992 atm
Moles = Mass / Molar mass
0.992 atm . 0.125L = (0.495 g / MM) . 0.082 . 371K
(0.992 atm . 0.125L) / (0.082 . 371K) = (0.495 g / MM)
4.07x10⁻³ mol = 0.495 g / MM
MM = 0.495 g / 4.07x10⁻³ mol → 121.4 g/m
The color is an effect as a result of different wavelengths and frequencies of the light waves. So, color is a property of an object that depends on the wavelength. From all the given statements the following is true: T<span>he color depends upon the lighting source. More precisely, the color depends upon the wavelength of the lighting source.</span>
Answer: D. Potassium bromide
Thus BeF2 is of most covalent character.
Anyways, covalent/ionic character is a bit tricky to figure out; we measure the difference in electronegativity of two elements bonding together and we use the following rule of thumb: if the charge is 0 (or a little more), the bond is non-polar covalent; if the charge is > 0 but < 2.0 (some references say 1.7), the bond is polar covalent; if the charge is > 2.0 then the bond is ionic. Covalent character refers to smaller electronegativity difference while ionic character refers to greater electronegativity difference.
Now, notice all of our bonds are with F, fluorine, which has the highest electronegativity of 3.98. This means that to determine character we need to consider the electronegativities of the other elements -- whichever has the greatest electronegativity has the least difference and most covalent character.
Na, sodium, has electronegativity of 0.93, so our difference is ~3 -- meaning our bond is ionic. Ca, calcium, has 1.00, leaving our difference to again be ~3 and therefore the bond is ionic. Be, beryllium, has 1.57 yielding a difference of ~2.5, meaning we're still dealing with ionic bond. Cs, cesium, has 0.79, meaning our difference is again ~3 and therefore again our compound is of ionic bond. Lastly, we have Sr, strontium, with an electronegativity of 0.95 and therefore again a difference of roughly 3 and an ionic bond.
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