Work out the percentage composition of constituents elements in the following compounds:
Potassium dichromate `(K_2Cr_2O_7)`

Work out the percentage composition of constituents elements in the following compounds: Lead phosphate [Pb_3(PO_4)_2]

Work out the percentage composition of constituents elements in the following compounds: Macrocosmic salt - Sodium ammonium hydrogen phosphate tetrahydrate (NaNh_4HPO_4*4H_2O) (At. ,ass : Pb = 207, P = 31, O = 16, K = 39, Cr =52, Na =23, N=14)

Assign oxidation number to each element in the following compounds or ions. K_2Cr_2 O_7

Find the oxidation number of nitrogen in the following compounds : N_2O_3 .

Assign oxidation number to each element in the following compounds or ions. Ca_3 (PO_4)_2

Find the oxidation numbers of the underlined species in the following compounds or ions. K_2 Cr _2O_7 .

Find the out the molar masses of the following compounds: Sodium carbonate, decahydrate (Na_2CO_3*10H_2O)

Calculate the mass percentage composition of the elements in nitric acid (H=1 ,N=14, O=16) .