why alkali metals are powerful reducing agent?
819689
Because the effective losing of an electron can be coupled with harder to reduce substances.
813459
Alkaline metals like lithium, sodium and potassium etc in  pure form would float in water is added to them. But that would be only part of the reaction because simultaneously  they are reacting with the water, producing hydrogen bubbles which buoy them up. Potassium producing enough that it bursts into flame normally and sodium sometimes depending on the size of chunk. The remaining alkali metals all have explosive reactions with water.
957199
If you are doing it in a laboratory setting, you can mix it with carbon and reduce it to the metal. You will need high temperatures, though.
846677
Great question Angel V, you get a thumbs up, >from me<.\n\nAs you move down a group, metals become more reactive.\n\nThis is because of three reasons. \nI) Electrons farther from the nucleus are easier to get rid of because the positive nucleus is so far away\nII) Electrons farther from the nucleus already have lots of energy ready to be put to use in an exothermic process\nIII) Valence electrons have lots of electrons underneath them, causing what is known as shielding\n\nNote: I just thought I would add: It is not necessarelly true that the farther accross a period you go the elements are less reactive. For instance cadmium is more reactive than gold.
689214
Obviously, being Alkili metals, these elements would reaction vigorously with water to produce Hydrogen gas (which would soon ignite) and the metal Hydroxide.\nJudging from the trend which can be seen by comparing reaction of Lithium, Sodium, and Potassium with water, as you move down the group, the reaction become more violent.\n\nOne could calculate the exact energy released by using the enthalpies of formation and solution of the compounds.\n\nAlso, as you move down the group, the elements become rarer and rarer.\nFrancium is very instable (even the most stable isotope) and will only exist in a laboratory for a short time.
334010
The only way I've heard of to obtain pure sodium metal is by electrolysis of NaCl.  Basically, place the salt solution between two electrodes (Na+ attracted to anode, Cl- attracted to cathode).\n\nPure Na is extremely reactive, though.  It is very difficult to store, as any exposure to air will cause almost instant oxidation of the surface (formation of Na2O).  There is also very little commercial use for pure Na.  There are many, many commercially viable sodium compounds, but pure sodium is rarely useful.
751854
It does completely. High melting points arise when the atoms of a substance interact and form strong inter-molecular bonds. These are weaker than ionic bonds and covalent bonds but work on the same principle. If the distance between the two atoms is great, the bond strength is low and vice versa. Thus, since potassium has a larger atomic radius, the inter-molecular bonds are weak and it is easier to melt a sample of potassium.
427800
In each half-cell is a chemical undergoing either oxidation or reduction. In a full electrochemical cell, one side must be losing electrons (oxidation) in to its electrode while the other half-cell gains electrons (reduction). If the atoms/ions involved in the reaction are metal, the same metal is used for each electrode. If the atoms/ions involved in the reaction at each half-cell are not metal, obviously no electrode can be constructed out of it. Nonreactive metals such as platinum are used as a substitute. Finally, a salt bridge is necessary to provide electrical contact between the cells—but without the solutions mixing. This can simply be a strip of filter paper soaked in saturated potassium nitrate (V) solution.\n\nDifferent choices of substances for each half-cell results in varying potential differences. Each reaction is undergoing an equilibrium reaction between different oxidation states of the ions—when equilibrium is reached the cell cannot provide further voltage. In the half-cell which is undergoing oxidation, the closer the equilibrium lies to the ion/atom with the more positive oxidation state the more potential this reaction will provide. Similarly, in the reduction reaction, the further the equilibrium lies to the ion/atom with the more negative oxidation state the higher the potential.
1094317
aluminium because its an alkali earh metal and\nfluorine is a halogen
468302
they oxidize. they are positive (+2, +3....), so have empty spots in their electron shell.  they want to stabilize, so absorb some electrons.  oxygen has -2, they go together and stabilize.\nmetals are reactive in pure metal form, like pure sodium metal. so they are usually submerged in a liquid, or kept in with another gas. like pure sodium metal is submerged in kerosene (i think, kerosene)
709082
The word alkali comes from the Arabic word for "ashes," where the oxides of these metals were first found. Alkali is now used as another word for base (see acids and bases); when the ashes containing the oxides of the alkali metals are dissolved in water, a base is formed. For example, sodium oxide dissolved in water yields sodium hydroxide, or lye.
233865
Generally, the elements that form ionic bonds tend to have either very high or very low electronegativity. This means the Alkali metals, Alkaline Earth metals, and the Halogens, especially when reacting with each other.
704477
CO is not a powerful enough reducing agent to reduce CaO.\nPerhaps the questioner meant carbon dioxide?\nIn which case the equilibrium is simple:\n\nCaO + CO2 <-----> CaCO3
772321
The alkali metals, found in group 1 of the periodic table (formerly known as group IA), are very reactive metals that do not occur freely in nature. These metals have only one electron in their outer shell. Therefore, they are ready to lose that one electron in ionic bonding with other elements. As with all metals, the alkali metals are malleable, ductile, and are good conductors of heat and electricity. The alkali metals are softer than most other metals. Cesium and francium are the most reactive elements in this group. Alkali metals can explode if they are exposed to water. \n\nThe alkaline earth elements are metallic elements found in the second group of the periodic table. All alkaline earth elements have an oxidation number of +2, making them very reactive. Because of their reactivity, the alkaline metals are not found free in nature.
68791
Reactivity in goup 1 increses down the group from Lithium to Sodium to Potassium. Therefore, Sodium would the closest. They are all group 1 metals, just in different periods. All have one vacant electron which makes them very reactive.
22494
Potassium Permanganate is an oxidant which will accept electrons depending on the pH at the time of the reaction. In neutral to alkaline solutions, it will form insolubile manganese oxide (MnO2), accepting three electrons, in acid solutions it will form Mn2+ ions.\n\nOxalate is an organic acid rest with a C-C bond and the sum formula (CO2)2 2-. It reacts as a reductive agent and will donate two electrons and accept negative charged two Oxygen atoms (from the water or the Permanganate), forming two carbonate ions.\n\nStrictly speaking, not carbon dioxide but dissolved sodium and  potassium carbonate will be the product of the reaction.
784768
Groups, and moreover every property becomes more pronounced as you move from one member to another of a group  That is to say, Sodium is more reactive than Lithium, Potassium more than Sodium. Rubidium more than Potassium, Cesium more than Rubidium, Francium more than Cesium. Their melting points decrease as you move through the group. Cesium for instance would melt in your hand, if you wouldn't mind the severe burns, and Francium, if it could be formed in quantity, would be even lower melting.