Answer:
pH = 4.543
Explanation:
- CH3CH2COOH + H2O ↔ CH3CH2COO- + H3O+
- pKa = - Log Ka
∴ Ka = [H3O+][CH3CH2COO-]/[CH3CH2COOH]
∴ pKa = 4.87
⇒ Ka = 1.349 E-5 = [H3O+][CH3CH2COO-]/[CH3CH2COOH]
added 300 mL 0f 0.02 M NaOH:
⇒ <em>C</em> CH3CH2COOH = ((0.200 L)(0.15 M)) - ((0.300 L)(0.02 M))/(0.3 + 0.2)
⇒ <em>C</em> CH3CH2COOH = 0.048 M
⇒ <em>C</em> NaOH = (0.300 L)(0.02 M) / (0.3 +0.2) = 0.012 M
mass balance:
⇒ 0.048 + 0.012 = 0.06 M = [CH3CH2COO-] + [CH3CH2COOH].......(1)
charge balance:
⇒ [H3O+] + [Na+] = [CH3CH2COO-]
∴ [Na+] = 0.02 M
⇒ [CH3CH2COO-] = [H3O+] + 0.02 M.............(2)
(2) in (1):
⇒ [CH3CH2COOH] = 0.06 M - 0.02 M - [H3O+] = 0.04 M - [H3O+]
replacing in Ka:
⇒ 1.349 E-5 = [H3O+][([H3O+] + 0.02) / (0.04 - [H3O+])
⇒ (1.349 E-5)(0.04 - [H3O+]) = [H3O+]² + 0.02[H3O+]
⇒ 5.396 E-7 - 1.349 E-5[H3O+] = [H3O+]² + 0.02[H3O+]
⇒ [H3O+]² + 0.02001[H3O+] - 5.396 E-7 = 0
⇒ [H3O+ ] = 2.867 E-5 M
∴ pH = - Log [H3O+]
⇒ pH = 4.543
The flow of stimuli information in the body is from the receptors to sensory neuron (afferent neurons) to the interneurons then to the central nervous system (brain and spinal cord) then is carried of by the motor neurons (efferent neurons) to the mucles involve.
Sensation to transduction to perception. Sensation is the ambiguous information which is received by the receptors or sensory organ henceforth, transduction occurs in the nerve cell protruding to the brain and is now called perception as the vague stimuli is interpreted and processed to be understood then is responded with the proper and apt response or reaction.
<>"One such trend is closely linked to atomic radii -- ionic radii. Neutral atoms tend to increase in size down a group and decrease across a period. When a neutral atom gains or loses an electron, creating an anion or cation, the atom's radius increases or decreases, respectively."<>
The compound nitrogen have most positive oxidation state is NO₂. The correct option is b.
<h3>What is oxidation state?</h3>
The total number of electrons gained or lost by an atom in order to form a chemical bond with another atom.
The charge on an ion is equal to the sum of the oxidation states of all the atoms in the ion. A substance's more electronegative elements are given a negative oxidation state.
A positive oxidation state is assigned to the less electronegative element.
Thus, the correct option is b, NO₂.
Learn more about oxidation state
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