Titration
what is the pH at the half equivalence point of a HF titration.
PKa for HF = 3.8
3.8
is entropy conserved like enthalpy, energy, and mass
no entropy can be created but not destroyed. It's not a form of energy like heat.
what is the Ksp equation for Ca(OH)2
Ksp=[Ca2+][OH-]2
what is the pH of a 10 molar solution of HCl
-log(10)=-1
does it matter if the McRib and exercise mats both share a certain chemical.
No many chemicals have many uses. these are likely the share many chemicals. cellulose for example is the primary chemicals of most plants fiber and is likely in both.
you are titrating 15mL of 0.5M solution of acetic acid with a 0.1 M solution of NaOH. How many mL need to be added in order to reach the equivalence point
15mL * 0.5M / 0.1m = 75mL
is a reaction has a delta H of -4kJ/mol is it endo- or exo- thermic.
exothermic. the chemical is looking 4kJ/mol to the environment.
In pure water AlPO4 has a Ksp of 9.84*10-21 what is it's solubility?
sqrt(9.84*10-21) = 9.92*10-11
what is the pH of a 1M solution of HF
HF pKa=3.8
-log(sqrt(1.58*10-4 * 1M))
pH=1.9
Name a chemical,that isn't water, you'd commonly find in the body. (chemical not element, carbon doesn't work)
many answers:
glucose, lipids, GABA, Hemoglobin, protein
how many mols of sodium acetate would you add to 1 mol of acetic acid to make a 4.5 pH buffer.
pKa for acetic acid = 4.760.55 mols of sodium acetate
10(4.5-4.76)=0.55 mol
CaCO3(s) -> CaO(s) + CO2(g)
DeltaH is positive
when is the reaction favored
at high tempratures
you can tell the entropy is positive bc it makes gas.
what concentration of SO42- is needed start precipitating BaSO4 from a 0.1M solution of Ba2+
BaSO4 Ksp=1.08*10-10
1.08*10-9M SO42-
Ksp=[SO42-][Ba2+]
if you have 1L of unbuffered 14 pH solution and you add 1 mol of HCl. what is the new pH?
hint:use pOH
[OH-] = 1014-14 = 1M OH-
1M OH- - 1M H+ = 0M OH remaining.
pH = 7
What does Hydrofluoric acid do to you if you're exposed to it.
Skeletal fluorosis: makes bones brittle
pKa CH3COOH = 4.76
4.76 + log(0.1M*5mL / (15mL * 0.5M - 5ml * 0.1M)
=3.61
if one reaction has a delta G of 1kJ/mol and another has a delta G of 105 kJ/mol. do you know which one will react faster.
you cannot know. themodynamics is completely removed from reaction speed.
CdF2 Ksp = 6.44*10-3
CaF2 Ksp = 3.45*10-11if F- is added to a solution of Cd2+ and Ca2+ which salt will first fall out of solution.
CaF2 the less soluble ion will be the first to fall out.
If you have a mixture of strong and weak acid. How do you calculate the pH. assume the weak acid is non negligable.
use the strong acid for the initial concentration of H+ when doing the ICE table for the weak acid.
what is the oxidation state of Mn in MnO4-
+7
-2*4 + +7 = -1
what is the pH at the equivalence point for 10mL 0.1M solution of NH3 being titrated with a 0.1M solution of HCl.
PKa of NH4+ = 9.24
C = 0.1M*10mL/20mL
pH = -log(sqrt(Ka*C))
5.3
What is the Delta G for the reaction at 25C
H2 + 0.5O2 -> H2O
H2O Delta Hf = -285kJ/mol
H2O Sf = 69.95 J/mol*K
G = -285000 - 69.95 * (25+273)
= -305.8kJ/mol
the solubility of Al(OH)3 in a pH 10 solution is 3*10-22. What is the Ksp
Ksp=[OH]3[Al]
[OH] = 10pH-14
3*10-34
what is the pKa of an acid with a pH of 4 when
[HA] = 2[A-] = 5
4= pKa + log(5/2)
pKa = 3.6
What is Sebastian's favorite piece of glassware?
Soxhlet extractor. They're awesome.