Answer
a) $29.8\ g$
b) $14.3\ g$
c) $12.6\ g$
d) $23.6\ g$
Work Step by Step
Atomic weights: $O: 15.999u,\ C: 12.011u,\ H:1.008u,\ N: 14.007u$
a) $C_{14}H_{10}O_4$: $M = 14\times12.01 + 10\times1.008+4\times15.999=242.2\ g/mol$
$0.123\ mol \times 242.2\ g/mol = 29.8\ g$
b) $C_{4}H_{8}O_2N_2$: $M = 4\times12.01 + 8\times1.008+2\times15.999+2\times14.007=116.1\ g/mol$
$0.123\ mol \times 116.1\ g/mol = 14.3\ g$
c) $C_5H_{10}S$: $M = 5\times12.01 + 10\times1.008+32.06=102.2\ g/mol$
$0.123\ mol \times 102.2\ g/mol = 12.6\ g$
d) $C_{12}H_{17}ON$: $M = 12\times12.01 + 17\times1.008+15.999+14.007=191.3\ g/mol$
$0.123\ mol \times 191.3\ g/mol = 23.6\ g$
