Endothermic reactions are reactions that proceed by the absorption of heat (energy) while exothermic reactions involve a release of energy.
a) Formation of frost on a car window in winter is an exothermic process as heat is liberated when liquid water freezes to form crystals
b) Formation of water condensate on a glass of ice water is an endothermic reaction since heat is absorbed by the cold water from the glass container thereby cooling it.
c) A decrease in the temperature as ammonium nitrate is added to water is an endothermic reaction
You need to have 8 electrons to fill an atom and to fill bond the pairs need to equal 8
Answer:
A.It lowers the melting point of alumina. B.It increases the electrical conductivity. ... Hint: The solution of alumina and cryolite during the electrolysis gives the aluminium at cathode and oxygen at anode. The alumina is a poor conductor of electricity and the fusion temperature of alumina is about 2000∘C.
Answer: C) Bent or angular, polar
Explanation:
The central atom oxygen has two lone pairs and two bond pairs in . The number of electron pairs are 4, that means the hybridization will be and the electronic geometry of the molecule will be tetrahedral. But as there are two lone pair of atoms around the central oxygen atom, repulsion between lone and bond pair of electrons is more and hence the molecular geometry will be bent shape.
The compound is polar as the net dipole moment of oxygen - fluoride bonds do not cancel each other out.
Answer:
The log will float on the water because its density is lower than the liquid, so it will stay at the top due to Archimedes' principle.