Answer:
1.16 mL
Explanation:
Assume the data show that 25 pennies have a total volume of 29.00 mL.
Answer:
The most effective buffer at pH 9.25 will be a mixture of 1.0 M NH3 and 1.0 M NH4Cl
Explanation:
Step 1: Data given
pH of a buffer = pKa + log ([A-]/[Ha])
a mixture of 1.0 M HC2H3O2 and 1.0 M NaC2H3O2 (Ka for acetic acid = 1.8 x 10-5)
pH = -log( 1.8 * 10^-5) + log (1/1)
pH = -log( 1.8 * 10^-5)
pH = 4.74
a mixture of 1.0 M NaCN and 1.0 M KCN (Ka for HCN = 4.9 x 10-10)
pH = -log( 4.9 * 10^-10) + log (1/1)
pH = -log( 1.8 * 10^-5)
pH = 9.30
a mixture of 1.0 M HCl and 1.0 M NaCl
The solution made from NaCl and HCl will NOT act as a buffer.
HCl is a strong acid while NaCl is salt of strong acid and strong base which do not from buffer solutions hence due to HCl PH is less than 7.
a mixture of 1.0 M NH3 and 1.0 M NH4Cl (Kb for ammonia = 1.76 x 10^-5)
Ka * Kb = 1*10^-14
Ka = 10^-14 / 1.76*10^-5
Ka = 5.68*10^-10
pH = -log( 5.68*10^-10) + log (1/1)
pH = -log( 5.68*10^-10)
pH = 9.25
The most effective buffer at pH 9.25 will be a mixture of 1.0 M NH3 and 1.0 M NH4Cl
Answer:
Oxidation state] is defined as the charge an atom might be imagined to have when electrons are counted according to an agreed-upon set of rules:
The oxidation state of a free element (uncombined element) is zero for a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion.
Hydrogen has an oxidation state of 1 and oxygen has an oxidation state of −2 when they are present in most compounds. (Exceptions to this are that hydrogen has an oxidation state of −1 in hydrides of active metals, e.g. LiH, and oxygen has an oxidation state of −1 in peroxides, e.g. H2O2 the algebraic sum of oxidation states of all atoms in a neutral molecule must be zero, while in ions the algebraic sum of the oxidation states of the constituent atoms must be equal to the charge on the ion.
The same is written in my textbook. But how am I supposed to find the ox. number of an atom, which is in compound like K2UO4?
Answer:
D. It is limited to situations that involve aqueous solutions or specific compounds.
Explanation:
An Arrhenius acid is a substance that increases the concentration of H3O or H+ when dissolved in water. An Arrhenius base is a substance that increases the concentration of OH- when dissolved in water. These definitions tell us that D is indeed limited to situations that involve aqueous solutions or specific compounds, as aqueous means something that's dissolved in water.
A is wrong because the Bronsted-Lowry interpretation has a wider range of applications. Bronsted-Lowry acids and bases don't even need to be aqueous, so it is not limited to just aqueous solutions. They include any substance that can donate or accept a H+.
B is wrong because A is wrong. A and B basically say the same thing, that the Arrhenius interpretation has a wider range of applications than the Bronsted-Lowry interpretation.
C is wrong because the definition of an Arrhenius base is any substance that increases the concentration of OH-, or hydroxide ions. C completely counters this statement.
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