A 200.0-mL sample of helium gas is in a cylinder with a movable piston at 110 kPa and 275 K. The piston is pushed in until the sample has a volume of 95.0 mL. The new temperature of the gas is 310. K. What is the new pressure of the sample? 51.1 kPa
261 kPa
249 kPa
274 kPa

P₂ = 261 KPa

Explanation:

Given data:

Volume of sample = 200 mL

Initial pressure = 110 KPa

Initial temperature = 275 K

Final volume = 95 mL

Final temperature = 310 K

Final pressure = ?

Solution:

Formula:

P₁V₁/T₁ = P₂V₂/T₂

P₂ = P₁V₁T₂ /T₁ V₂

P₂ = 110 KPa× 200 mL× 310 K /275 K  × 95 mL

P₂ = 6820000 KPa / 26125

P₂ = 261 KPa

the answer is d. 74.02

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.