Answer:
pH = 2.69
Explanation:
The complete question is:<em> An analytical chemist is titrating 182.2 mL of a 1.200 M solution of nitrous acid (HNO2) with a solution of 0.8400 M KOH. The pKa of nitrous acid is 3.35. Calculate the pH of the acid solution after the chemist has added 46.44 mL of the KOH solution to it.</em>
<em />
The reaction of HNO₂ with KOH is:
HNO₂ + KOH → NO₂⁻ + H₂O + K⁺
Moles of HNO₂ and KOH that react are:
HNO₂ = 0.1822L × (1.200mol / L) = <em>0.21864 moles HNO₂</em>
KOH = 0.04644L × (0.8400mol / L) = <em>0.0390 moles KOH</em>
That means after the reaction, moles of HNO₂ and NO₂⁻ after the reaction are:
NO₂⁻ = 0.03900 moles KOH = moles NO₂⁻
HNO₂ = 0.21864 moles HNO₂ - 0.03900 moles = 0.17964 moles HNO₂
It is possible to find the pH of this buffer (<em>Mixture of a weak acid, HNO₂ with the conjugate base, NO₂⁻), </em>using H-H equation for this system:
pH = pKa + log₁₀ [NO₂⁻] / [HNO₂]
pH = 3.35 + log₁₀ [0.03900mol] / [0.17964mol]
<h3>pH = 2.69</h3>
Answer:
Aluminum , iron , gold , silver , nickels etc are the type of elements form metallic bonds .
The name transition metal refers to the position in the periodic table of elements. The transition elements represent the successive addition of electrons to the d atomic orbitals of the atoms. In this way, the transition metals represent the transition between group 2 (2A) elements and group 13 (3A) elements.
5) state
when the state of the chemical changes that is the most important
Answer:
Approximately 6.81 × 10⁵ Pa.
Assumption: carbon dioxide behaves like an ideal gas.
Explanation:
Look up the relative atomic mass of carbon and oxygen on a modern periodic table:
Calculate the molar mass of carbon dioxide :
.
Find the number of moles of molecules in that sample of :
.
If carbon dioxide behaves like an ideal gas, it should satisfy the ideal gas equation when it is inside a container:
,
where
- is the pressure inside the container.
- is the volume of the container.
- is the number of moles of particles (molecules, or atoms in case of noble gases) in the gas.
- is the ideal gas constant.
- is the absolute temperature of the gas.
Rearrange the equation to find an expression for , the pressure inside the container.
.
Look up the ideal gas constant in the appropriate units.
.
Evaluate the expression for :
.
Apply dimensional analysis to verify the unit of pressure.