Answer
a) 159.808 amu
b) 34.014 amu
c) 183.18 amu
d) 194.189 amu
Work Step by Step
a) Formula mass = 2×Atomic mass of Br = 2× 79.904amu= 159.808 amu
b) Formula mass = 2×Atomic mass of H + 2×Atomic mass of O = 2× 1.008amu+ 2×15.999 amu = 34.014 amu
c) Formula mass= 7×Atomic mass of C + 5×Atomic mass of H + Atomic mass of N + Atomic mass of S + 3× Atomic mass of O = 7×12.0107amu + 5×1.008amu+ 14.0067amu + 32.065amu+ 3×15.999 amu = 183.18 amu
d) Formula mass = 2×Atomic mass of K + Atomic mass of Cr+ 4×Atomic mass of O = 2×39.0983 amu + 51.9961 amu+ 4×15.999 amu = 194.189 amu