Which correctly lists the following in order of increasing entropy? i. 1 mol of hcl (g) at 50 ° c ii. 1 mol of nacl (s) at 25 ° c iii. 2 mol of hcl (g) at 50 ° c iv. 1 mol of hcl (g) at 25 ° c

The order of increasing entropy will be:

1 mol of NaCl (s) at 25 ° C < 1 mol of HCl (g) at 25 ° C<  1 mol of HCl (g) at 50 ° C < 2 mol of HCl (g) at 50 ° C

Explanation:

The entropy increases with

a) increase in temperature

b) state of matter (the entropy order of matter is gas > liquid > solid)

So here

i) 1 mol of HCl (g) at 50 ° C : it is gas at high temperature as compared to HCl gas at lower temperature.

ii. 1 mol of NaCl (s) at 25 ° C : this is solid so will have lower entropy than gas.

iii. 2 mol of HCl (g) at 50 ° C: the moles are more so will have more entropy than 1 mol of HCl (g) at 50 ° C

iv. 1 mol of HCl (g) at 25 ° C : will have lower entropy than HCl gas at higher temperature but will have higher entropy than solid NaCl.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance