1. A nonmetal is extracted from seawater. It is soluble in water. It gives out red brown fumes
with an unpleasant smell. Identify this nonmetal and state two uses of this nonmetal.
2. Identify a nonmetal used to provide low temperature for storage of blood. Why is this
nonmetal used for the same?
Answers
Answer:
for minor operations, especially in dentistry. It is called laughing gas because of its intoxicating effect. It is also widely used as a propellant in aerosol cans of whipped cream. Nitric oxide, NO, can be created in several ways. The lightning that occurs during thunderstorms brings about the direct union of nitrogen and oxygen in the air to produce small amounts of nitric oxide, as does heating the two elements together. Commercially, nitric oxide is produced by burning ammonia (NH3), whereas in the laboratory it can be produced by the reduction of dilute nitric acid with, for example, copper (Cu).
3Cu 8HNO3 → 2NO + + 4H2O
Gaseous nitric oxide is the most thermally stable oxide of nitrogen and is also the simplest known thermally stable paramagnetic molecule—i.e., a molecule with an unpaired electron. It is one of the environmental pollutants generated by engines, resulting from the reaction of nitrogen and oxygen in the air during the combustion process. At room temperature nitric oxide is a colourless gas consisting of diatomic molecules. However, because of the unpaired electron, two molecules can combine to form a dimer by coupling their unpaired electrons.
2NO ⇌
Thus, liquid nitric oxide is partially dimerized, and the solid consists solely of dimers.
When a mixture of equal parts of nitric oxide and nitrogen dioxide, , is cooled to −21 °C (−6 °F), the gases form trioxide, a blue liquid consisting of molecules. This molecule exists only in the liquid and solid states. by heating the nitrate of a heavy metal, as in the following equation,
2Pb()2 + heat → 2PbO + 4NO2 + O2,
or by adding copper metal to concentrated nitric acid. Like nitric oxide, the nitrogen dioxide molecule is paramagnetic. Its unpaired electron is responsible for its colour and its . At low pressures or at high temperatures, has a deep brown colour, but at low temperatures the colour almost completely disappears as dimerizes to form tetroxide At room temperature an equilibrium between the two molecules exists.
2NO2 pentoxide, N2O5, is a white solid formed by the dehydration of nitric acid by phosphorus(V) oxide.
P4O10 + 4HNO3 → 4HPO3 + 2N2O5
Above room temperature is unstable and decomposes to N2O4 and O2. Two oxides of nitrogen are acid anhydrides; that is, they react with water to form nitrogen-containing oxyacids.