Answer:
1. pH = 1.23.
2. 
Explanation:
Hello!
1. In this case, for the ionization of H2C2O4, we can write:
It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:
![pH=pKa+log(\frac{[base]}{[acid]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D%20%29)
Whereas the pKa is:
The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:
2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:
It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:
Which is also shown in net ionic notation.
Best regards!
C. Rubbing the balloon against your hair
The first step is to balance the equation:
<span>C3H8 + 5O2 ---> 3CO2 + 4H2O
Check the balance
element left side right side
C 3 3
H 8 4*2 = 8
O 5*2=10 3*2 + 4 = 10
Then you have the molar ratios:
3 mol C3H8 : 5 mol O2 : 3 mol CO2 : 4 mol H2O
Now you have 40 moles of O2 so you make the proportion:
40.0 mol O2 * [3 mol CO2 / 5 mol O2] = 24.0 mol CO2.
Answer: option D. 24.0 mol CO2
</span>
Enthalpy is energy of bonds broken - energy of bonds formed. Here, the NH3 and O2 are broken and H2O and NO are formed. So the energy to break the NH3 bonds is 3 times the amount of energy it takes to break a N-H single bond (because there are three of them in a NH3 molecule) and then multiplied by 4 because there are four particles.
So the energy of the bonds broken is 12x the energy to break a N-H single bond plus 5x the amount of energy to break an O—O double bond (you don’t multiply this by anything because in each O2 molecule there is only one bond).
The energy of the bonds formed is 6*2 = 12 Times the amount of energy for a O-H single bond plus 4 times the amount of energy required to break a N—O double bond.
Subtract energy of bonds broken - energy of bonds formed and this is the change in enthalpy.
To know what type of bond it is, draw the Lewis structure.
Answer:C
Explanation: ice molecules are solid
