Answer:
108.43 grams KNO₃
Explanation:
To solve this problem we use the formula:
Where
- ΔT is the temperature difference (14.5 K)
- Kf is the cryoscopic constant (1.86 K·m⁻¹)
- b is the molality of the solution (moles KNO₃ per kg of water)
- and<em> i</em> is the van't Hoff factor (2 for KNO₃)
We <u>solve for b</u>:
- 14.5 K = 1.86 K·m⁻¹ * b * 2
Using the given volume of water and its density (aprx. 1 g/mL) we <u>calculate the necessary moles of KNO₃</u>:
- 275 mL water ≅ 275 g water
- moles KNO₃ = molality * kg water = 3.90 * 0.275
- moles KNO₃ = 1.0725 moles KNO₃
Finally we <u>convert KNO₃ moles to grams</u>, using its molecular weight:
- 1.0725 moles KNO₃ * 101.103 g/mol = 108.43 grams KNO₃
Answer:
A
Explanation:
An unbalanced force is your answer.
Due to electronegativity difference between H and F atom.
<h3>
What is the reason for the difference ?</h3>
- The bond length of HF is 92 pm. It is 16% shorter than the sum of the covalent radii of H (37 pm) and F (72 pm).
- The shorter of the bond length is due to the difference in electronegativity between H and F atom. The electronegativity of F is 4.0, whereas the electronegativity of H is 2.1.
- Greater the difference of electronegativity between the bonded atoms, shorter will be the bond length.
- As becomes smaller i.e. as we proceed from HF to HI, this effect becomes lessens and bond length will be more predictable.
Thus from the above conclusion we can say the difference in electronegativity between H and F atom this is the reason for shorter bond length of HF.
Learn more about bond length here :
brainly.com/question/13683866
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