Answer
$$75.3 \space JK^{-1}mol^{-1}$$
Work Step by Step
1. Determine the molar mass of water $\big(H_2O\big)$
$H: 1.01 \times 2 = 2.02$
$O: 16.00 \times 1 = 16.00$
$16.00 + 2.02 = 18.02 \space g/mol$
2. Multiply the specific heat capacity of water by its molar mass, in order to calculate its molar heat capacity:
$$C_m = C_s \times ({molar \space mass})$$ $$C_m = 4.18 \space JK^{-1} g^{-1} \times 18.02 \space g/mol = 75.3 \space JK^{-1}mol^{-1}$$
