acids and bases
what does it mean for a reaction to be in equilibrium?
The rate of the forward and reverse reactions are equal.
a solution with a pH of 4.21 is (acidic or basic)
acidic
Buffers are made from
weak acids and their conjugate base
The point in a titration at which the moles of titrant equal the moles of analyte.
Name the four primary types of radiation.
Alpha, Beta, Gamma, Neutron
Write the Keq for the following reaction
CaCl2 (aq) + K2CO3 (aq) --> 2KCl (aq) + CaCO3 (s)
[KCl]^2/[CaCl2][K2CO3]
What is the conjugate base of NH4
NH3+
A solution with a low pKa is (acidic or basic)
a titration graph is what shape?
S shaped (or backwards S)
What does it mean if an acid is polyprotic?
it can donate multiple protons (H+)
If H2O is added to this reaction which way will the reaction shift?
H2O +CO2 <--> HCO3- +H+
right, towards the products.
what species will be present after this reaction occurs?
HBr (aq) + H2O (l)(excess) --> H3O+ (aq) + Br- (aq)
H2O, H3O+, and Br-
Write the Ka for the following reaction
HCO3- (aq) + H2O (l) <--> CO3 2- (aq) + H3O+ (aq)
Ka= [CO3 2-][H3O+]/[HCO3-]
25.0 mL of 0.150 M sodium hydroxide is added to a flask containing 20.0 mL of hydrochloric acid with an unknown molarity. Which solution is the analyte?
HCl (hydrochloric acid)
A 1000 g sample of Technetium 99m is left for 2 and a half days. It has a half life of 6 hours, how much is left?
0.9765 g
Corrected for sig figs: 1 g
What is an amphoteric species?
A compound that can act as an acid or a base under different conditions.
The pH of a solution is 5.63, what is the Hydronium ion concentration?
2.34 x 10 ^-6
What buffer system is used by the human body to maintain blood pH?
The bicarbonate buffer system
what does it mean when the pH> pKa in a buffer solution?
There is more conjugate base than conjugate acid
Iodine-131 has a half life of 8.0 days. How many days will it take for a 200 g sample to decay to 12.5 g?
32 days
Identify the conjugate acid base pairs for the reaction.
CH3COOH + H2O <--> CH3COO- + H3O+
CH3COOH and CH3COO-
H2O and H3O+
Find the pH of a solution that has a hydroxide concentration of 4.35 x10^-7.
7.64
How much sodium formate (HCOONa, 68.0069 g/mol) do you need to add to 400. mL of 1.00 M formic acid for a pH 3.500 buffer. Ka = 1.77 x 10¯4
15.2 g
a 0.1 M NaOH solution is added to a 25 mL HCl solution with an unknown molarity. It takes 20. ml of NaOH to reach the equivalence point. What is the concentration of HCl? (monoprotic)
HCl (aq) + NaOH (aq) --> NaCl (aq) + H2O (l)
0.08M
A sample of Cobalt-60 (half life of 5.26 years) has 50.0 g remaining after 15.8 years. What was the original mass of the sample?
400g