Question

For each system listed in the first column of the table below, decide (if possible) whether the change described in the second column will increase the entropy of the system, decrease S, or leave S unchanged. If you don't have enough information to decide, check the "not enough information" button in the last colur Note for advanced students: you may assume ideal gas and ideal solution behaviour. AS System Change AS<0 The seawater is passed through a reyerse-osmosis filter, which AS 0 separates it into 750. mL of pure A liter of seawater at 15°C. O AS 0 water and 250. mL of brine (very salty water). not enough information AS <0 O AS 0 An additional 2.0 L of pure Ar gas A mixture of nitrogen (N) gas and is added to the mixture, with the O AS> 0 argon (Ar) gas at 4 atm and 15°C. pressure kept constant at 4 atm. not enough information AS< 0 The solution put into a AS = 0 A 0.35 Msolution of sucrose in semiperme mmersed in the .. water, and 50. mL of pure water water, and a beaker of pure water, boaler O As 0 both at 37.°C flows through the bag into the sucrose solution. O not enough info O OO

Answer 1

1ltr of sea water : ∆S < 0

Due to reverse osmosis , concentration of system increases , water molecules are removed from system, entropy would decreases. Osmosis is spontaneous phenomenon due to which entropy increases but in case of reverse osmosis entropy would deceases.

A mixture of nitrogen and argon gas at 4atm and 15℃ : ∆S > 0

As the more number of moles of argon is added to the system, the randomness would increases and hence the entropy would increases.

A 0.35M solution of sucrose in water and a beaker of pure water at 37℃ : ∆S > 0

As the solution is placed in semipermeable bag and water molecules enter the solurion i.e. osmosis. The process is spontaneous and hence it would increases the entropy .