Answer:
All of the above processes have a ΔS < 0.
Explanation:
ΔS represents change in entropy of a system. Entropy refers to the degree of disorderliness of a system.
The question requests us to identify the process that has a negative change of entropy.
carbon dioxide(g) → carbon dioxide(s)
There is a change in state from gas to solid. Solid particles are more ordered than gas particles so this is a negative change in entropy.
water freezes
There is a change in state from liquid to solid. Solid particles are more ordered than liquid particles so this is a negative change in entropy.
propanol (g, at 555 K) → propanol (g, at 400 K)
Temperature is directly proportional to entropy, this means higher temperature leads t higher entropy.
This reaction highlights a drop in temperature which means a negative change in entropy.
methyl alcohol condenses
Condensation is the change in state from gas to liquid. Liquid particles are more ordered than gas particles so this is a negative change in entropy.
Parantheses mean present of a subgroup or a group of polyatomic ions in a chemical reaction.
<u>Explanation:</u>
In a chemical reaction, sometimes, a compound may be composed of group of polyatomic ions with other ions. Some of the polyatomic ions are sulfate, carbonate, nitrate, hydroxide, bicarbonate, ammonia etc.
So these polyatomic ions are formed by combining two or more elements. Thus, if the number of polyatomic ions in a compound is more than one, then we use parathesis and write those polyatomic ions in it and write the number of polyatomic ions present in the compound as subscript of the parathesis.
For example, Fe₂(SO₄)₃
So here SO₄ is a polyatomic ion and in the compound 3 atoms of SO₄ is required to neutralize the compound and thus paranthesis is used. Thus, parantheses mean present of a subgroup or a group of polyatomic ions in a chemical reaction.
Answer:
632.32 mmHg
Explanation:
Millimetre mercury:
It is the monometric unit of pressure. It is define as "The pressure exerted by the column pf mercury at the height of 1 millimetre.
It is represented as mmHg.
It can also be written as mm Hg.
Atmosphere (atm):
It is barometric pressure, define as "The force exerted by atmospheric column on per unit area".
It is written as "atm".
Conversion of atm to mmHg:
0.832 atm × 760 mmHg / 1 atm
632.32 mmHg
Answer:
pH= 0.92
Explanation:
HNO3-> H^+ +NO3^-
HNO3 is a strong acid, so it fully dissociates
[HNO3] = 0.12M [H^+] = 0.12M
pH= -log[H^+]
pH=-log[.12] = 0.92
pH = 0.92
