Chemistry
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
Answer
(i) Molecular mass of Na2SO4.10H2O
= 2 x 23 + 32 + 4 x 16 + 10(2 x 1 + 16)
= 46 + 32 + 64 + 180
= 322 amu
(ii) Molecular mass of (NH4)2CO3
= 2(14 + 4 x 1) + 12 + 3 x 16
= 36 + 12 + 48
= 96 amu
(iii) Molecular mass of (NH2)2CO
= 2(14 + 2 x 1) + 12 + 16
= 32 + 12 + 16
= 60 amu
(iv) Molecular mass of Mg3N2
= 3 x 24 + 2 x 14
= 72 + 28
= 100 amu
Related Questions
Elements X, Y and Z have 3, 7 and 6 electrons in their valence shells respectively. Write the formula of the compound formed between :
(a) X and Y
(b) X and Z
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 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]
Find the percentage mass of water in Epsom salt, MgSO4.7H2O.