Tag: chemistry

Sodium is a light and soft metal that reacts vigorously with cold water. Sodium when dropped in cold water forms a ball and moves on the surface of cold water with sodium hydroxide formation accompanied with the release of hydrogen gas.
$2Na+2H _2O \rightarrow 2NaOH +H _2$

Metals like aluminium, zinc, iron do not react with hot/cold water ; they react only with steam to form a metal oxide and hydrogen .

Sodium is highly reactive with cold water forming hydroxides and hydrogen gas. Hence, sodium is always stored under kerosene. Mercury, zinc and tungsten are found in the reactivity series at the bottom and are not highly reactive compared to sodium.

Metals form basic or amphoteric oxides while non metals form acidic oxides.

Aluminium is soft silvery metal, yet the surface gets tarnished due to the formation of film of its oxide $Al _2O _3$.
When aluminium is exposed to moist air a thin film of  oxide layer which is thin, hard and adhering.
$4Al+3O _2 \rightarrow 2Al _2O _3$

Metal + Oxygen $\rightarrow$ Metallic oxide

s-p overlapping one such type of overlapping. Here there is a overlapping between the s- and p- orbital's of the molecules. This type of overlapping is generally seen in the NH3 molecules. This formed by overlapping between 3 orbital's of hydrogen and 3 of nitrogen

Actually the oxides of metals like Zn,Pb and other metals which are not very reactive can be reduced by Carbon. However oxides of very reactive metals (eg Aluminium,Chromium) can't be reduced by Carbon . Since they are very reactive they react with carbon to form their carbides hence are not effective in reduction.

$2Al(s) + 3H _2O(g) \rightarrow Al _2O _3(s) + 3H _2(g)$