Final answer:
The mass of a pure gold bar that displaces 0.82 liters of water is approximately 15.77 kg, given the density of gold is 19.3 g/cm³.
Step-by-step explanation:
To determine the mass of a pure gold metal bar that displaces 0.82 L of water, we use the density of gold which is given as 19.3 g/cm³. First, we will convert the volume from liters to cubic centimeters, since there are 1000 cubic centimeters in a liter, the volume of the gold bar in cubic centimeters is 0.82 L × 1000 cm³/L = 820 cm³. Then we can calculate the mass of the gold in grams using the density formula: mass = density × volume. This gives us:
mass = 19.3 g/cm³ × 820 cm³
The mass of the gold bar is therefore 15826 g, or 15.826 kg when converted to kilograms (since 1 kg = 1000 g). Thus, the correct answer is (b) 15.77 kg, which is approximately the calculated mass of 15.826 kg after rounding to two decimal places.