Answer:
Enthalpy change = 333.3 J
Explanation:
Given data:
Volume of helium = 11.2 dm³ or 11.2 L
Temperature = 100 °C (100+273= 373 K)
Enthalpy change = ?
Solution:
Normal temperature of room = 20°C (20+273 = 293 K)
one mole of gas occupy volume = 22.4 L
ΔT = final temperature - initial temperature
ΔT = 373K - 293K
ΔT = 80K
Number of moles of gas = 11.2 L/22.4 l
Number of moles of gas = 0.5 mol
Enthalpy change = nRΔT
Enthalpy change = 0.5 mol × 8.3j/mol.k ×80 K
Enthalpy change = 333.3 J
Answer:
V₂ = 568.9 mL
Explanation:
Given data:
Initial volume of gas = 550 mL
Initial pressure of a gas = 960 mmHg
Initial temperature = 200.0°C
Final volume = ?
Final pressure = 830 mmHg
Final temperature = 150°C
Solution:
Initial temperature = 200.0°C ( 200+273 = 473 K)
Final temperature = 150°C (150+273 = 423 K)
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
P₁V₁/T₁ = P₂V₂/T₂
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 960 mmHg × 550 mL × 423 K / 473 K ×830 mmHg
V₂ = 223344000 mL / 392590
V₂ = 568.9 mL
I think the correct answer from the choices listed above is option A. The three components of air are all <span>classified as pure substances since they are not chemically bonded so they can be separated by certain processes and be present as a pure substance. Hope this answers the question.</span>
Alkenes such as ethene have at least one double bond in their chains and these join to make a polymer called polyethene but alkanes like ethane have only single bonds
Answer:
The answer to your question is pH = 9.5
Explanation:
Data
pOH = 4.5
pH = ?
pH measures the hydronium concentration [H₃O⁺]. The scale of pH goes form 0 to 14. If the solution has a pH from 0 to 6.9 the solution is an acid, if the pH = 7, the solution is neutral and if the pH goes from 7.1 to 14 the solution is an alkali,
Formula
pH + pOH = 14
-Solve for pH
pH = 14 - pOH
-Substitution
pH = 14 - 4.5
-Result
pH = 9.5