Which of the following properties will change when system containing solution 1 will become solution 2 ?
10 mol of solute x; +; 10 L of water, →, 1 L of solution 1; +; 1 mol of solute x; +; 1 L of water; (Solution 1), (Solution 2)

Solution

Chemistry ma’am · 3 steps

Same recipe, smaller batch: only a property that depends on how much you have can change.

1. Compare the compositions. Solution 1 has 10 mol of x per 10 L of water, that is 1 mol per litre of water. Any portion taken from it keeps this ratio, and adding 1 mol of x with 1 L of water keeps it too. So solution 2 has exactly the same composition as solution 1.
2. Only the amount changes. Solution 1 has 10 mol of x in 10 L of water. Solution 2 has about 2 mol of x in about 2 L of water. Intensive properties depend only on composition, so they stay the same. Extensive properties scale with the amount of matter, so they change.

   Property	Type	Changes?
   Molar heat capacity	intensive (heat capacity per mole)	no
   Concentration	intensive (amount of solute per volume)	no
   Gibbs free energy G	extensive	yes, it falls with the smaller amount
   Density	intensive (mass per volume)	no

3. So. Solution 2 is the same solution in a smaller quantity, so only the extensive property, the Gibbs free energy, changes. The answer is (c).

The idea to keep. Same composition, different amount? Intensive properties (concentration, density, any molar quantity) stay fixed. Only extensive ones such as G, H, U, mass and volume change.

Answer from the NTA final answer key. Solution by PrepWiser.