What happens to valence electrons in ionic bonding? this is a question i know but gives me answer choices im not sure about

Which aqueous solution has the highest boiling point at standard pressure?(1) 1.0 M KC1(aq) (3) 2.0 M KCl(aq)(2) 1.0 M CaC12(aq)

miss Akunina [59]

Answer:

(4) 2.0 M CaCl₂(aq).

Explanation:

Adding solute to water elevates the boiling point.

The elevation in boiling point (ΔTb) can be calculated using the relation:

ΔTb = i.Kb.m,

where, ΔTb is the elevation in boiling point.

i is the van 't Hoff factor.

van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass. For most non-electrolytes dissolved in water, the van 't Hoff factor is essentially 1.

Kb is the molal elevation constant of water.

m is the molality of the solution.

(1) 1.0 M KCl(aq):

i for KCl = no. of particles produced when the substance is dissolved/no. of original particle = 2/1 = 2.

suppose molarity = molality, m = 1.0 m,

∴ ΔTb for (1.0 M KCl) = i.Kb.m = (2)(Kb)(1.0 m) = 2(Kb).

(2) 2.0 M KCl(aq):

i for KCl = no. of particles produced when the substance is dissolved/no. of original particle = 2/1 = 2.

suppose molarity = molality, m = 2.0 m,

∴ ΔTb for (1.0 M KCl) = i.Kb.m = (2)(Kb)(2.0 m) = 4(Kb).

(3) 1.0 M CaCl₂(aq):

i for CaCl₂ = no. of particles produced when the substance is dissolved/no. of original particle = 3/1 = 3.

suppose molarity = molality, m = 1.0 m,

∴ ΔTb for (1.0 M KCl) = i.Kb.m = (3)(Kb)(1.0 m) = 3(Kb).

(4) 2.0 M CaCl₂(aq):

i for CaCl₂ = no. of particles produced when the substance is dissolved/no. of original particle = 3/1 = 3.

suppose molarity = molality, m = 2.0 m,

∴ ΔTb for (1.0 M KCl) = i.Kb.m = (3)(Kb)(2.0 m) = 6(Kb).

So, the aqueous solution has the highest boiling point at standard pressure is: (4) 2.0 M CaCl₂(aq).

6 0

3 years ago

Post-Lab Questions

Svet_ta [14]

Answer:

1. not enough dye was added to the drink.

The wrong dye was added to the drink

the water in the drink is evaporating

2. Changing the compound changes the absorbance behavior.

3. Measure the absorbance for the same solution in different cuvette sizes and find the y-intercept.

Explanation:

When the beverage company adds dye to the drink, there should be standard quantity added to the drink so that the color of the drink remains constant. When too much dye is added to the drink, the color will get dark brown or black. When the color of drink get lighter than green this means dye is not added in required quantity.

7 0

2 years ago

Volume of water displaced = 0.175 L Mass g Density g/cm3 Hardness: = Determine the unknown mineral. Unknown mineral: 7

erastovalidia [21]

Answer:

Mass: 981.0 g

Density: 5.61 g/cm^3

Hardness: = 2.5 - 3

Unknown material: Chalcocite

Explanation:

5 0

2 years ago

HELP PLSSSSS!!

11Alexandr11 [23.1K]

Answer:

68133080.02 g

Explanation:

I believe that the question is to find the mass of air in the room and not the molar mass of air since the molar mass of air was already given in the question as 28.97 g/mol.

Now, if 1 mole of a gas occupies 22.4 L

x moles of air occupies 52,681,428.8 Liters

x = 1 * 52,681,428.8 /22.4

x = 2351849.5 moles of air

Now, number of moles = mass/ molar mass

but molar mass = 28.97 g/mol

2351849.5 = mass/28.97

mass = 2351849.5 * 28.97

mass = 68133080.02 g

7 0

3 years ago

Which substance is a binary acid

Bumek [7]

It is known that acids compounds contains hydrogen and produces hydrogen ion in water. A binary acid however is an acid that have two elements, one of the element has a hydrogen attached to it. Examples of binary acids are hydrogen fluoride (HF), hydrogen bromide (HBr) and hydrogen sulfide (H2S). In naming a binary acid, it has two rules; one, as pure compounds and two, as acid solutions. For pure compounds, start with the name ‘hydrogen’ and end the anion name with ‘-ide’. For acidic compounds, start with ‘hydro-‘, end the anion with ‘-ic’ and add ‘acid’.

4 0

2 years ago