Please help with question 11( Idk how do you tell?) 12 ( please explain what wou
ID: 503526 • Letter: P
Question
Please help with question 11( Idk how do you tell?) 12 ( please explain what would happen in exothermic and endothermic reaction) 15 ( How do you know acid/base? I always get confused) Department of Chemistry Brooklyn College General Chemistry II; Spring 2017 Lecture Exam 1 Name: .8. (2 pts) Find the molarity of an HCIO4(ag) solution whose pHis 150 (givs your final answsawith3 0.03 6 3.16 YIo Memon .9. (2 pts) The molarity of an Ca (OH)( .10. (4 pts) Give the formula of a conjugate acid of PH b.-conjugate base of HCO3 .11. (2 pts) which one of the following molecules cannot be a weak basc? none can be a base all can be bases (e) (a) H2S; (b) NF (c) PC .12. (4 pts) We have the following reaction at equilibrium: Alg) +B() e 20(g DKg) with AH 290.0 kJ/mol. What happens to the concentration of Alif (select from in decreases, or stays the same) (a) the temperature is increased? decea e decree sea (b) the pressure of the system is increased at constant temperature? .13. (4 pts we have the following reaction at equilibrium: Ale Ble with AH 90.0 kJimo changes)? (a) What happens to the value of Qc when we add some D (no volume Ingrea (b) What happens to the value of Ac when we add some D (no volume changes)? arte (select from increases, decreases, or stays the same) .15. (8 pts) Classify each of these solutions as acidic, basic, orneutral. H NAse Br or NHYBr H-20 SNL Naciou no (c) CuCl2(aq) (d) KF (ag)Explanation / Answer
Q11.
Weak base --> can receive H+ protons...
H2S --> this can be, since H3S+ could theoretically form.. Note that in reality, this is not likely to happen
NF3 --> Nitrogen han, in theory, accept H+ in its lonepair, therefore this could be
PCl5 --> has no more lone pairs... therefore
The best anwer will be "none" since they are not likely to accept H+ protons
Q12
The reaction is EXOTHERMIC, since it has negative dHRxn, meaning it will release heat as reaction goes forward
therefore,
if we increase T, this means we increase HEAT, which does NOT favour produts, only reactants
Therefore, for [A], expect a increase in concentration
b)
If we increase P, this favours mainly the least mol formation
reactant side = 1+1 = 2 moles of gas
produt side = 2+1 = 3
therefore, the least mol are in the reactants side, expect A to increase in conentration
Q15
a) NH4Br --> NH4+ + Br- --> NH4+ donate H+, therefore acidic
b)
NaCLO4 --> Na+ + ClO4-
ClO4- is strong, will not ionize, so pH = neutral
c)
CuCl2 --> Cu+ + 2Cl-
Cu+ is likely to form H+ via Cu(OH) preicpitation, this is slightly acidic