Answer:
4.99 × 10³ g/mol
Explanation:
Step 1: Given and required data
- Mass of the covalent compound (m): 62.4 g
- Volume of the solution (V): 1.000 L
- Osmotic pressure (π): 0.305 atm
- Temperature (T): 25°C = 298 K
Step 2: Calculate the molarity (M) of the solution
The osmotic pressure is a colligative pressure. For a covalent compound, it can be calculated using the following expression.
π = M × R × T
M = π / R × T
M = 0.305 atm / (0.0821 atm.L/mol.K) × 298 K
M = 0.0125 M
Step 3: Calculate the moles of solute (n)
We will use the definition of molarity.
M = n / V
n = M × V
n = 0.0125 mol/L × 1.000 L = 0.0125 mol
Step 4: Calculate the molar mass of the compound
0.0125 moles of the compound weigh 62.4 g. The molar mass is:
62.4 g/0.0125 mol = 4.99 × 10³ g/mol
Answer:2 ml.
Explanation:Volume. 2.5 g/ml = 5g/Volume. Volume = 5g/(2.5 g/ml). = 2 ml.
Answer:
∆H = -763kJ
Explanation:
Using Hess's law we can determine the ΔH of a reaction from the sum of similar reactions. Using the reactions:
<em>(1) </em>2PCl3(l) → 2P(s) + 3Cl2(g) ∆H = -640 kJ
<em>(2) </em>2P(s) + 5Cl2(g) → 2PCl5(s) ∆H = -886 kJ
The sum of (1)/2 + (2)/2 gives:
(1) / 2 = PCl3(l) → P(s) + 3/2Cl2(g) ∆H = -640 kJ/2 = -320kJ
(2) / 2 = P(s) + 5/2Cl2(g) → PCl5(s) ∆H = -886 kJ/2 = -443kJ
PCl3(l) + Cl2(g) → PCl5(s) ∆H = -320kJ - 443kJ =
<h3>∆H = -763kJ
</h3>
Complete question is;
When solid materials are heated.the heat absorbed/added to the materials caused the materials to change its form from?
Answer:
From solid to liquid
Explanation:
When we heat solid materials, the heat causes the forces of attraction between the molecules to become weaker and as such, the material becomes more loose than it was in the solid state. As a result, the material now becomes a liquid because the molecules now have lesser forces of attraction and are a bit loose.
