Answer:
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Explanation:
The lowering of the freezing point of a solvent is a colligative property ruled by the formula:
Where:
- ΔTf is the lowering of the freezing point
- Kf is the molal freezing constant of the solvent: 1.86 °C/m
- m is the molality of the solution
- i is the van't Hoff factor: the number of particles (ions) per unit of ionic compound.
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<u>a) molality, m</u>
- m = number of moles of solute/ kg of solvent
- number of moles of CaI₂ = mass in grams/ molar mass
- number of moles of CaI₂ = 25.00g / 293.887 g/mol = 0.0850667mol
- m = 0.0850667mol/1.25 kg = 0.068053m
<u>b) i</u>
- Each unit of CaI₂, ideally, dissociates into 1 Ca⁺ ion and 2 I⁻ ions. Thus, i = 1 + 2 = 3
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<u>c) Freezing point lowering</u>
- ΔTf = 1.86 °C/m × 0.068053m × 3 = 0.3797ºC ≈ 0.380ºC
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14. a. Acidic
15. b. Weaker
16. d. Dilute and weak
Explanation:
14. Which type of the solution is one with the pH of 3?
Solution with pH from 1 to 7 are acidic, equal to 7 is neutral and from 7 to 14 basic. The solution with the pH equal to 3 is <u>acidic</u>.
15. The smaller the value of the base dissociation constant (Kb), the <u>weaker</u> the base.
The dissociation reaction of a base (B) is:
B + H₂O → BH⁺ + OH⁻
Kb is defined as:
Kb = ( [BH⁺] × [OH⁻] ) / ( [B] × [H₂O] )
The potency of the base depends on the concentration of the hydroxide ion [OH⁻], so if the Kb ratio is small it means that the concentration of hydroxide ion is smaller so the base will be <u>weaker</u>.
16. A 0.39 M solution of an acid that ionizes only slightly in solution would be termed <u>dilute and weak</u>.
The acid is weak because is only slightly ionizing in solution. The therm diluted is a little bit arbitrarily because we ask yourself "diluted in respect with what"? I would characterize the acid to be diluted at a concentration of 1 M and concentrated at a concentration of 10 M.
Learn more about:
pH
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Answer:
A its a step by step equation the answer is A
A. An Interdependent system of plants, animals, and land
Democritus, theorized that atoms were specific to the material which they composed. In addition, Democritus believed that the atoms differed in size and shape, were in constant motion in a void, collided with each other; and during these collisions, could rebound or stick together.
<u>Explanation:</u>
- One of the main atomic theorists was Democritus, a Greek philosopher who lived in the fifth century BC. Democritus realized that if a stone was partitioned fifty-fifty, the two parts would have indistinguishable properties from the whole.
- Therefore, he contemplated that if the stone were to be constantly cut into littler and littler pieces at that point; sooner or later, there would be a piece that would be so little as to be inseparable. He called these small pieces of matter as "atomos", the Greek word for inseparable.
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Democritus estimated that atoms were explicit to the material which they made. Also, Democritus accepted that the particles varied in size, were an inconsistent shape, crashed into one another; and during these impacts, could bounce back or stay together. Hence, changes in the matter were a consequence of separations or mixes of the atoms as they moved all through the void.
