Answer
(i) 780. g
(ii) 2.90 N
Work Step by Step
1. Calculate the molar mass of benzene $\big(C_6H_6\big)$:
$C: 12.0 \times 6 = 72.0$
$H: 1.0 \times 6 =6.0$
Molar mass of benzene = $72.0 + 6.0 = 78.0 \space g/mol$
2. Find the mass of 10.0 mol $C_6H_6$:
$$10.0 \space mol \times \frac{78.0 \space g}{1 \space mol} = 780. \space g$$
3. Calculate the weight on the surface of Mars:
$Weight = mg = (780. \space g)(3.72 \space m/s^2) = 2.90 \times 10^3 \space g \space m/s^2$
Normally, the weight is expressed in $N$, which is $kg \space m/s^2$. Thus, we should convert the mass into $kg$:
$1 \space kg = 10^3 \space g$
$$Weight = 2.90 \times 10^3 \space g \space m/s^2 = 2.90 \space kg \space m/s^2 = 2.90 \space N$$
