Answer:
- <em>The vapor pressure of the solution at 25°C is </em><u><em>23.6 mmHg</em></u>
Explanation:
<u>1) Data:</u>
- Mass of solute, sucroese, m₁ = 40.0 g
- Mass of solvent, water, m₂ = 250. g
- Vapor pressure of solution, p = ?
- Vapor pressure of pure water, p⁰ = 23.76 mm Hg
<u>2) Principles and formulae:</u>
- Raoult's law states that the vapor pressure of a solution is equal to the mole fraction of the solvent times the vapor pressure of the pure liquid.
p = X p⁰
<u>3) Solution:</u>
a) <u>Mole fraction of the solvent (water)</u>
- X = number of moles of solvent / number of moles of solution
- number of moles of solvent, n₁ = mass in grams / molar mass
n₁ = 250. g / 18.015 g/mol = 13.88 moles
- number of moles of solute, n₂ = mass in grams / molar mass
n₂ = 40.0 g / 342,3 g/mol = 0.12 moles
- total number of moles, n₁ + n₂ = 13.88 moles + 0.12 moles = 14.0 moles
- moles fraction of water, X = 13.88 moles / 14.0 moles = 0.99
b) <u>Vapor pressure of the solution</u>:
- p = p⁰ X = 23.76 mmHg × 0.99 = 23.56 mm Hg
Rounding to three significant figures: 23.6 mm Hg.
Answer:
I
Explanation:
Among the halogens given in this problem, iodine has the lowest attraction for electrons.
This property is known as electronegativity.
Electronegativity is expressed as the relative tendency with which the atoms of the element attracts valence electrons in a chemical bond.
- As you go down the periodic group the electronegativity decreases.
- The most electronegative element on the periodic table is fluorine.
- Down the group, iodine is the least electronegative
- This is due to the large size of its atom.
Answer:
Kc = 9.52.
Explanation:
<em>A + 2B ⇌ C,</em>
Kc = [C]/[A][B]²,
Concentration: [A] [B] [C]
At start: 0.3 M 1.05 M 0.55 M
At equilibrium: 0.3 - x 1.05 - 2x 0.55 + x
0.14 M 1.05 - 2x 0.71 M
- For the concentration of [A]:
∵ 0.3 M - x = 0.14 M.
∴ x = 0.3 M - 0.14 M = 0.16 M.
∴ [B] at equilibrium = 1.05 - 2x = 1.05 M -2(0.16) = 0.73 M.
<em>∵ Kc = [C]/[A][B]²</em>
∴ Kc = (0.71)/(0.14)(0.73)² = 9.5166 ≅ 9.52.
Answer;
-Acceleration: 10 km/h/s east
Explanation;
-The quantity is either a vector or a scalar. Scalars are quantities that are fully described by a magnitude (or numerical value) alone while Vectors are quantities that are fully described by both a magnitude and a direction.
Acceleration is a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity.
In this case , a =( v-u)/t ; where a is the acceleration, v is the final velocity, u is the initial velocity and t is time.
a = (60 - 0)/6
= 10 km/h/s
Answer:
Carbonate
Explanation:
Carbonate is a combination of a carbon atom and two oxygen atoms for form a compound.