Decide which atom or atoms have been oxidised and reduced, when the following compounds are formed from their elements.
`SO_2, H_2 O, H_2 S, NH_3, HF, BF_3`

Arrange the following in decreasing order of their bond angle ': H_2 O, NH_3, H_2 S'

If an element is in its highest possibel oxidation state in a compound, it can act as an oxidising agent. If an element is in its lowest possible oxidation state in a compound, if can act as reducing agent. If an element is in the intermediate oxidation state in a compound, it can serve as both oxidising and reducing agent. Based on the above three guidelines, classify the following compounds into three categories and post them in the table given below. KMnO_4 , H_2O_2 , H_2C_2O_4 , FeSO_4 , HCIO_4 , SO_2 , Na_2S_2O_3 , K_2Cr_2O_7

In which of the following S has highest oxidation state? Na_2 S_2 O_6 , S_2 Cl_2 , S_8 , H_2 SO_4

What are hybridisation states of each carbon atom in the following compounds? CH_2 = C = O, CH_3CH=CH_2(CH_3)_2CO, CH_2= CHCN, C_6H_6

Identify the o0XIdant and reductant and the atoms undergoing o0XIdation and reduction in the following redox reactions. H_2S + 2HNO_3 to 2NO_2 + 2H_2O + S

Classify the molecule in to ionic, covalent, those obeying octet rule and those not obeying octet rule. Make a table for answer. NaCl, H_2O , O_2 , KCl, BF_3 , PCl_5 , NH_3 .

Electronegativity values of some elements are given. Using these values, find whether the following compounds are ionic or covalent. (Electronegativity of Ca=1, O=3.5, C=2.5, S=2.58,H=2.2,F=3.98 ) Sulphur dioxide (SO_2) .

Which of the following is not formed when H_2S , reacts with acidic K_2Cr_2O_7 , solution?