Search results
Results from the WOW.Com Content Network
For example, acetic acid is a weak acid which has a = 1.75 x 10 −5. Its conjugate base is the acetate ion with K b = 10 −14 /K a = 5.7 x 10 −10 (from the relationship K a × K b = 10 −14), which certainly does not correspond to a strong base. The conjugate of a weak acid is often a weak base and vice versa.
Raters were high-school teachers, who brought the rating system back to their schools. [45] One teacher was Albert Lavin, who installed similar holistic scoring at Sir Francis Drake High School in Marin County, California, 1966–1972, at grades 9, 10, 11, and 12 in order to show progress in school writing over those years. [ 46 ]
In water, measurable pK a values range from about −2 for a strong acid to about 12 for a very weak acid (or strong base). A buffer solution of a desired pH can be prepared as a mixture of a weak acid and its conjugate base. In practice, the mixture can be created by dissolving the acid in water, and adding the requisite amount of strong acid ...
However, for weak acids, a quadratic equation must be solved, and for weak bases, a cubic equation is required. In general, a set of non-linear simultaneous equations must be solved. Water itself is a weak acid and a weak base, so its dissociation must be taken into account at high pH and low solute concentration (see Amphoterism).
The researchers concluded that a rubric that had higher reliability would result in greater results to their "review-revise-resubmit procedure". [25] Anti Rubric: Rubrics both measure the quality of writing, and reflect an individual's beliefs of what a department or particular institution’s rhetorical values. But rubrics lack detail on how ...
The higher the proton affinity, the stronger the base and the weaker the conjugate acid in the gas phase.The (reportedly) strongest known base is the ortho-diethynylbenzene dianion (E pa = 1843 kJ/mol), [3] followed by the methanide anion (E pa = 1743 kJ/mol) and the hydride ion (E pa = 1675 kJ/mol), [4] making methane the weakest proton acid [5] in the gas phase, followed by dihydrogen.
Holistic rubrics provide an overall rating for a piece of work, considering all aspects. Analytic rubrics evaluate various dimensions or components separately. Developmental rubrics, a subset of analytical rubrics, facilitate assessment, instructional design, and transformative learning through multiple dimensions of developmental successions.
Conversely, the addition of acid converts weak acid anions to CO 2 and continuous addition of strong acids can cause the alkalinity to become less than zero. [12] For example, the following reactions take place during the addition of acid to a typical seawater solution: B(OH) − 4 + H + → B(OH) 3 + H 2 O OH − + H + → H 2 O PO 3− 4 + 2 ...