Answer is: D. Na2SO4.
b(solution) = 0.500 mol ÷ 2.0 L.
b(solution) = 0.250 mol/L.
b(solution) = 0.250 m; molality of the solutions.
ΔT = Kf · b(solution) · i.
Kf - the freezing point depression constant.
i - Van 't Hoff factor.
Dissociation of sodium sulfate in water: Na₂SO₄(aq) → 2Na⁺(aq) + SO₄²⁻(aq).
Sodium sulfate dissociates on sodium cations and sulfate anion, sodium sulfate has approximately i = 3.
Sodium chloride (NaCl) and potassium iodide (KI) have Van 't Hoff factor approximately i = 2.
Carbon dioxide (CO₂) has covalent bonds (i = 1, do not dissociate on ions).
Because molality and the freezing point depression constant are constant, greatest freezing point lowering is solution with highest Van 't Hoff factor.
Answer:
4.59 × 10⁻³⁶ kJ/photon
Explanation:
Step 1: Given and required data
- Wavelength of the violet light (λ): 433 nm
- Planck's constant (h): 6.63 × 10⁻³⁴ J.s
- Speed of light (c): 3.00 × 10⁸ m/s
Step 2: Convert "λ" to meters
We will use the conversion factor 1 m = 10⁹ nm.
433 nm × 1 m/10⁹ nm = 4.33 × 10⁷ m
Step 3: Calculate the energy (E) of the photon
We will use the Planck-Einstein's relation.
E = h × c/λ
E = 6.63 × 10⁻³⁴ J.s × (3.00 × 10⁸ m/s)/4.33 × 10⁷ m
E = 4.59 × 10⁻³³ J = 4.59 × 10⁻³⁶ kJ
Answer:
Explanation:
We are given the formula:
This is a molecular formula, because it contains nonmetals.
1. Name the first element
The first element is phosphorous (P). Since this is the first element and there is only one, we don't need a prefix.
2. Second element
The second element is chlorine (Cl). It has a subscript of 5, so we must add the prefix of <u>hepta</u>-.
- Phosphorous heptachlorine
Add the ending of -ide.
- Phosphorous heptachloride
The prefix used for the second element is hepta. The compound name is phosphorous heptachloride.
Answer:
Increasing the temperature will cause chemical changes to occur faster. Decreasing the temperature, causes the particles to lose energy which causes them to move around less and slower. The less they move, the less collisions occur, and the less reactions occur between the chemicals = slower reaction rate.
Explanation: