15. How many covalent bonds are present in pentane (C,H,2) ?
SHORT ANSWER TYPE QUESTIONS (2 Marks)
1. What are hydrocarbons ? Give examples.
2. Why does carbon atom forms a large number of compounds ?
3. Write down two characteristics of the compounds of an homologous series.
4. Covalent compounds generally don't conduct electricity. Why?
5. Write down structural formula of:
(a) Propanone
(b) Hexanal
6. Why carbon is unique in nature ?
Science Class - 10
Answers
Answer:
15) Pentane has 16 covalent bonds
1.)carbon compounds containg hydrogen...Examples ==>pentane, Butane etc..
2).because each carbon atom can form four chemical bonds to other atoms, and because the carbon atom is just the right, small size to fit in comfortably as parts of very large molecules.
3).(1)All compounds have same general formula
(2)Difference between two consecutive Compounds is CH2
4). because they do not produce ions in water
5).C3H5O
.C6H14O
6)Carbon is the only element that can form so many different compounds because each carbon atom can form four chemical bonds to other atoms
There are 4 covalent bonds in pentane
Explanation:
1) Hydrocarbon are usually the compounds formed by the covalent bonding of hydrogen and carbon. They also may contain some other elements such as O,S etc
2)carbon atom forms a large number of atoms because it has a self linking property called catenation by which it can combine with many atoms to form compounds generally covalent
3)Two characteristics of compounds in homologues series are-
a)There is a difference of CH2 and molecular weight 14amu between two consecutive homologues compounds
b)They have names such as meth,eth,prop,pent etc.
4) Covalent compounds do not conduct electricity because they do not have ions to carry electrical charge.
6) Carbon is unique in nature because it has 4 valence electrons.If it gives those 4 electrons and if it takes 4 electrons it will be unstable.so it shares electrons and forms covalent compounds
