Answer:
For part (a): pHsol=2.22
Explanation:
I will show you how to solve part (a), so that you can use this example to solve part (b) on your own.
So, you're dealing with formic acid, HCOOH, a weak acid that does not dissociate completely in aqueous solution. This means that an equilibrium will be established between the unionized and ionized forms of the acid.
You can use an ICE table and the initial concentration ofthe acid to determine the concentrations of the conjugate base and of the hydronium ions tha are produced when the acid ionizes
HCOOH(aq]+H2O(l]⇌ HCOO−(aq] + H3O+(aq]
I 0.20 0 0
C (−x) (+x) (+x)
E (0.20−x) x x
You need to use the acid's pKa to determine its acid dissociation constant, Ka, which is equal to
Answer:
Q = 12.38
Explanation:
The Nernst equation is given as; Ecell = E°cell - (2.303RT/nF) log Q ;where Q is the reaction quotient.
The reaction quotient, Q in a reaction, is the product of the concentrations of the products divided by the product of the concentrations of the reactants.
In an electrochemical cell, Q is the ratio of the concentration of the electrolyte at the anode to that of the electrolyte at the cathode.
Q = [anode]/[cathode]
therefore , Q = 0.052/0.0042 = 12.38
Answer:
120,180,90.
Explanation:
PF3Br2 has a trigonal bypiramidal geometry. The three atoms of F will be arranged around the P atom in the same plane and each F-P-F bond will have an angle of 120 degrees. There will be only one Br atom above and beneath the P atom so the bond angle for Br-P-Br will be 180 degrees. Finally, the F−P−Br bond angle will be at 90 degrees.
First write the balanced equation of this reaction:
2H2 + O2 —> 2H2O
mol of H2= 0.60 gH2/2.02 gH2 = 0.297 mol
There are 2 mol of H2 for every 2 mol of H2O so the number of mol of H2 is equal to the number of mol of H2O.
g of H2O = 0.297 mol H2O • 18.02 gH2O = 5.35 g H2O
Do the same thing for O2:
mol of O2 = 4.8 gO2/32.0 gO2 = 0.15 mol of O2
There is 1 mol of O2 for every 2 mol of H2O so multiply 0.15 • 2 to get the number of mol of H2O
g of H2O = 0.30 mol H2O • 18.02 gH2O = 5.41 g H2O
The correct answer is 5.35 g H2O (or 5.4 g if checking significant figures) because O2, in this case, is the limiting reactant of this reaction.
