Ketones are trigonal planar about the ketonic carbon, with C-C-O and C-C-C bond angles of approximately 120 °.

Ketones may be distinguished from aldehydes by giving a negative result with Tollens ' reagent or with the Fehling's solution.

Ketones differ from aldehydes in that the carbonyl group ( CO ) is bonded to two carbons within a carbon skeleton.

Ketones are also distinct from other carbonyl-containing functional groups, such as carboxylic acids, esters and amides.

Ketones are hydrogen-bond acceptors.

Ketones are not usually hydrogen-bond donors and cannot hydrogen-bond to itself.

Ketones are classified on the basis of their substituents.

Ketones containing alkene and alkyne units are often called unsaturated ketones.

Ketones that have at least one alpha-hydrogen, undergo keto-enol tautomerization ; the tautomer is an enol.

Ketones ( acids ) are not typically present in the urine.

Ketones can be used by the brain as an alternate fuel when glucose is scarce.

# Use of Hydrogen Isotope Effects to Identify the Attacking Nucleophile in the Enolization of Ketones Catalyzed by Acetic Acid C. Gardner Swain, Edward C. Stivers, Joseph F. Reuwer, Jr. Lawrence J. Schaad ; J.

Debate rid us of McCarthy but did not give us much that is positive.

There were 49% ( 20 subjects ) who did not give a positive reaction even after they were informed of the normalcy of such a reaction and had been given a demonstration.

This subject, who has been undergoing psychoanalytic psychotherapy for five years, did not give a positive Kohnstamm reaction under any of the four standardized conditions used in this experiment while sober.

If the rake angle **yc of the knife is high enough and the friction angle **yt between the front of the knife and the back of the chip is low enough to give a positive value for Af, the resultant vector R will lie above the plane of the substrate.

Some euphemisms intend to amuse, while others intend to give positive appearances to negative events or even mislead entirely.

Also, macroscopic objects made of conductive elements, can more or less easily ( depending on the element ) take on or give off electrons, and then maintain a net negative or positive charge indefinitely.

The fructose will give a negative rotation, while the glucose will give a positive one.

Amino acids that make up proteins may be positive, negative, neutral, or polar in nature, and together give a protein its overall charge.

Methyl ketones give positive results for the iodoform test.

The metal dome switches are formed pieces of stainless steel that, when compressed, give the user a crisp, positive tactile feedback.

A specific longitude may then be combined with a specific latitude ( usually positive in the northern hemisphere ) to give a precise position on the Earth's surface.

While the first-order experiments could be explained by a modified stationary aether, more precise second-order experiments were expected to give positive results, however, no such results could be found.

Symbolically, the three inner circles, moving from the center outward, show that the three poisons of ignorance, attachment, and aversion give rise to positive and negative actions ; these actions and their results are called karma.

Proponents of positive rights, by attributing the protection of negative rights to the society rather than the government, respond that individuals would not have any rights in the absence of societies — a central tenet of communitarianism — and thus have a personal responsibility to give something back to it.

Since the supremum and infimum of an unbounded set of real numbers may not exist ( the reals are not a complete lattice ), it is convenient to consider sequences in the affinely extended real number system: we add the positive and negative infinities to the real line to give the complete totally ordered set, which is a complete lattice.

But if one partner is aware of being HIV positive, the other partner should expect a warning or if not, at least a truthful answer to the question, so they can give informed consent.

However, this does not mean that people seek tests that are guaranteed to give a positive answer.

Drum brake return springs give more positive action and, adjusted correctly, often have less drag when released.

A positive control is a procedure that is very similar to the actual experimental test but which is known from previous experience to give a positive result.

In 2008, it launched the " Save the Sea Kittens " campaign to change the name of fish to " sea kittens " to give them a positive image, and it regularly asks towns to adopt a new name.

Where there are two optical axes, the acute bisection of the axes gives Z for positive minerals and X for negative minerals and the obtuse bisection give the alternative axis ( X or Z ).

Here, for the case of squares inscribed in plane curves, we remove the restriction to convexity and give certain other results.

A domestic automatic washer that will give equivalent results may be used.

Fabrics that are badly distorted in their unlaundered state due to faulty finishing may give deceptive dimensional change results when laundered by any procedure.

Moreover, prudence alone would indicate that, unless the local customs are already ready to fall when pushed, the results of direct economic action everywhere upon national chain stores will likely be simply to give undue advantage to local and state stores which conform to these customs, leading to greater decentralization and local autonomy within the company, or even ( as the final self-defeat of an unjust application of economic pressure to correct injustice ) to its going out of business in certain sections of the country ( as, for that matter, the Quakers, who once had many meetings in the pre-Civil War South, largely went out of business in that part of the country over the slavery issue, never to recover a large number of southern adherents ).

The new quantum mechanics did not give exact results, but only the probabilities for the occurrence of a variety of possible such results.

In cases where the direction of the air motion is always the same, as in the ventilating shafts of mines and buildings for instance, wind vanes, known as air meters are employed, and give most satisfactory results.

The results of these tests give confidence to the clients as to how the system will perform in production.

Attempts to produce evolutionary " family trees " give results that differ from traditional classes because several of those classes are not monophyletic.

For an atemporal interpretation that “ makes no attempt to give a ‘ local ’ account on the level of determinate particles ”, the conjugate wavefunction, (" advanced " or time-reversed ) of the relativistic version of the wavefunction, and the so-called " retarded " or time-forward version are both regarded as real and the transactional interpretation results.

* ( Purely analytic proof of the theorem that between any two values which give results of opposite sign, there lies at least one real root of the equation ).

At present, the NAATs have regulatory approval only for testing urogenital specimens, although rapidly evolving research indicates that they may give reliable results on rectal specimens.

In an adiabatic system ( e. g. a system that does not give off heat to the surroundings ), an exothermic process results in an increase in temperature.

The benchmarks will give a much greater certainty that results can be compared with confidence in the date determinations, and such results will have farther scope than any evaluation based solely on local knowledge and conditions.

Its reaction with water results in insoluble indium ( III ) hydroxide, which is also amphoteric, reacting with alkalies to give indates ( III ) and with acids to give indium ( III ) salts:

The friction brake was adjusted according to a rower's weight to give an accurate appraisal of boat-moving ability ( drag on a boat is proportional to weight ). Inferior copies of Harrison's machine were produced in several countries utilising a smaller flywheel and leather straps-unfortunately the leather straps were sensitive to humidity, and the relatively large braking area made results far less accurate than Harrison's machine.

The characteristic property of the von Neumann measurement scheme is that repeating the same measurement will give the same results.

Clement X, seeing the results of the apostolic labours of the early French missionaries in Canada, the number of the faithful, and the wide field of labour, resolved to give the Church an independent organisation, and erected a see at Quebec, the bishop to depend directly on the Holy See ; this provision would later secure its permanence after Quebec passed into the hands of England.