Answer:
0.482 ×10²³ molecules
Explanation:
Given data:
Volume of gas = 2.5 L
Temperature of gas = 50°C (50+273 = 323 k)
Pressure of gas = 650 mmHg (650/760 =0.86 atm)
Molecules of N₂= ?
Solution:
PV= nRT
n = PV/RT
n = 0.86 atm × 2.5 L /0.0821 atm. mol⁻¹. k⁻¹. L × 323 k
n = 2.15 atm. L /26.52 atm. mol⁻¹.L
n = 0.08 mol
Number of moles of N₂ are 0.08 mol.
Number of molecules:
one mole = 6.022 ×10²³ molecules
0.08×6.022 ×10²³ = 0.482 ×10²³ molecules
Answer:
1) <em>The correct answer is A. Collision</em>
2) A hot solvent helps a solid dissolve faster because an increase in <u><em>kinetic energy</em></u> that also increases the rate of collisions
Explanation:
When a solute is added into a solvent and stirred, the solute particles get distributed to all parts of the solvent as a result of stirring.
More collisions occur between the solute and the solvent due to stirring. This increases the rate of dissolving.
<em>When a solvent is heated, then the kinetic energy would increase and the atoms will collide with a much greater force. As a result, ore solute will be able to dissolve in the solvent. </em>
Evaporation occurs when water molecules on the surface gain enough energy to enter the atmosphere. However, stronger intermolecular forces between water molecules cause them to be strongly attracted to each other and to tend to stay in the liquid phase. When the temperature is raised (when heat is applied), more molecules gain the energy needed to escape these intermolecular forces and go into the vapor phase.
Therefore the best answer is D.
