1. The conjugate acid-base pairs are HCl/Cl- and NH3/NH4+. They can be changed into one another by proton transfer.
2. The acid in the reaction is the molecule that has the lowest pKa value or (simply) gives their proton away the easiest. The pKa of HCl is around 3 I think while ammonia’s is around 35. This means HCl is the acid here. In the other reaction (backwards) you can see that NH4+ gives a proton to the chloride ion. To give a proton = acid. So the acids are HCl and NH4+ and the bases are NH3 and Cl-.
An important rule is: The stronger the acid/base, the weaker its conjugate base/acid.
First question is D, condensation
Second is B, convection
Answer:
Explanation:
in a combustion of ethane 2 moles of ethane react with 7 moles of O2
now no of moles in 54 gram of O2=mass/ molar mass
moles =54/32=1.7 moles
if 7 moles of O2 required 2 moles of ethane then 1.7 mole required=?
7 moles of O2=2 moles of C2H6
1.7 moles of O2=1.7*2/7=0.5 moles of C2H6
0.5 moles of C2H6 contain how much grams=?
mass= moles*molar mass=0.5*30=15
Answer:
3.45 moles Li contains 2.08
×
10
(to the power of)24 atoms
.
Explanation:
The relationship between atoms and moles is:
1 mole atoms
=
6.022
×
10
(to the power of)23
atoms
In order to determine how many atoms occupy a given number of moles, multiply the given moles by
6.022
×
10
(to the power of)23
atoms/mole
.
In the case of 3.45 moles lithium (Li):
3.45
mol Li
×
6.022
×
10
(to the power of)23 atoms Li/
1
mol Li
=
2.08
×
10
(to the power of)24
atoms Li rounded to three
