Chemistry
Calculate the relative molecular masses of
(a) CHCl3
(b) (NH4)2Cr2O7
(c) CuSO4.5H2O
(d) (NH4)2SO4
(e) CH3COONa
(f) Potassium chlorate, KClO3
(g) Ammonium chloroplatinate, (NH4)2PtCl6
[At. mass : C = 12, H = 1, O = 16, Cl = 35.5, N = 14, Cu = 63.5, S = 32, Na = 23, K = 39, Pt = 195, Ca = 40, P = 31, Mg = 24, Cr = 52]
Answer
(a) The relative molecular mass of CHCl3
= 12 + 1 + 3 x 35.5
= 12 + 1 + 106.5
= 119.5 amu
(b) The relative molecular mass of (NH4)2Cr2O7
= 2(14 + 4 x 1) + 2 x 52 + 7 x 16
= 36 + 104 + 112
= 252 amu
(c) The relative molecular mass of CuSO4.5H2O
= 63.5 + 32 + 4 x 16 + 5(2 x 1 + 16)
= 63.5 + 32 + 64 + 90
= 249.5 amu
(d) The relative molecular mass of (NH4)2SO4
= 2(14 + 4 x 1) + 32 + 4 x 16
= 36 + 32 + 64
= 132 amu
(e) The relative molecular mass of CH3COONa
= 12 + 3 + 12 + 16 + 16 + 23
= 82 amu
(f) The relative molecular mass of KClO3
= 39 + 35.5 + 3 x 16
= 39 + 35.5 + 48
= 122.5 amu
(g) The relative molecular mass of (NH4)2PtCl6
= 2(14 + 4 x 1) + 195 + 6 x 35.5
= 36 + 195 + 213
= 444 amu
Related Questions
The following figure represents the structural formula of a chemical compound.
Answer the questions given below:
(a) How many Carbon and Hydrogen atoms are present in the compound.
(b) Write the molecular and empirical formulae of the compound.
(c) Calculate the percentage composition of all the elements present in the compound. [At. wt. of C = 12, H = 1]
Calculate the molecular mass of the following :
(i) Na2SO4.10H2O
(ii) (NH4)2CO3
(iii) (NH2)2CO
(iv) Mg3N2
Given atomic mass of Na = 23, H = 1, O = 16, C = 12, N = 14, Mg = 24, S = 32
Find the percentage mass of water in Epsom salt, MgSO4.7H2O.
Calculate the percentage of phosphorus in:
(a) Calcium hydrogen phosphate, Ca(H2PO4)2
(b) Calcium phosphate, Ca3(PO4)2