A pure substance is found to be a good conductor of electricity in both its solid and liquid

What is the freezing point of an aqueous solution that has 25.00 g of calcium iodide dissolved in 1250 g of water?

ozzi

Answer:

- 0.380ºC

Explanation:

The lowering of the freezing point of a solvent is a colligative property ruled by the formula:

$\Delta T_f=K_f\times m\times i$

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.

a) molality, m

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

b) i

Each unit of CaI₂, ideally, dissociates into 1 Ca⁺ ion and 2 I⁻ ions. Thus, i = 1 + 2 = 3

c) Freezing point lowering

ΔTf = 1.86 °C/m × 0.068053m × 3 = 0.3797ºC ≈ 0.380ºC

<h2>I have problems to upload the full answer in here, so I attach a pdf file with the whole answer.</h2>

Download pdf

6 0

3 years ago

Help me, I’m failing chem

ladessa [460]

Answer:

b

Explanation:

[H3O+] = 10-pH = 10-3.4 ≅ 3.981 x 10^-4 moles/liter

5 0

3 years ago

Read 2 more answers

A voltaic cell using Cu/Cu²⁺ and Sn/Sn²⁺ half-cells is set up at standard conditions, and each compartment has a volume of 345 m

Nadusha1986 [10]

The mass of copper deposited is 9.589 g .

Given ,

A volatile cell using Cu/Cu2+ and Sn/Sn2+ half cells is set up at standard conditions ,and each compartment has a volume of 345 ml .

current = 0.17 A

time = 48 hrs =48 (60) (60) =172800 sec

we know , I = Q/t

thus , Q ,charge= It = 0.17 (17280) =29376 C

Then ,atomic mass of copper is 63 g

And valency of Cu is 2.

Thus , the equivalent mass of copper is 63/2 = 31.5

We know , 96500 coulombs of electricity produce copper = 31.5 g

29376 C of electricity produce copper =9.589 g

Hence , 9.589 g of Copper is deposited .

Learn more about charge here:

brainly.com/question/18102056

#SPJ4

4 0

1 year ago

0.0136 g + 2.70 × 10-4 g - 4.21 × 10-3 g = ? How many digits to the right of the decimal point should be used to report the resu

ki77a [65]

Consider the following equation:0.0136 g + 2.70 × 10-4 g - 4.21 × 10-3 g = ? How many digits to the right of the decimal point should be used to report the result? =2, Choose the correct answer=9.66 × 10^-3 g, Which metric unit would be the best choice to report the result?=mg

4 0

3 years ago

Read 2 more answers

Tyrone wants to buy peanut butter that does not contain any hydrogenated oils. What should Tyrone be concerned about?

Airida [17]

There are things that should be concerned about eating peanut butter. One would be the toxic fungus found within the peanut. Non-organic peanuts and peanut butters are also contaminated with pesticides.Peanuts also contain another natural substance called oxalates which can be toxic to the body.

3 0

3 years ago

Read 2 more answers