Given the following list of densities, which materials would float in a molten vat of lead provided that they do not themselves
melt? Densities (g/mL): lead = 11.4, glass = 2.6, gold = 19.3, charcoal = 0.57, platinum = 21.4. a. gold and platinum
b. glass and charcoal
c. gold, platinum, glass and coal
d. gold and charcoal
e. None of these
Step 2: Determine which material will float in molten lead
Density is an intrinsic property of matter. Less dense materials float in more dense materials. The materials whose density is lower than that of lead and will therefore float on it are glass and charcoal.
The answer is (2) KNO3. This depends on the solubility of these four compounds at 10℃. For NaCl, it is 35.8 g, For NaNO3, 80.8 g. KCl, 31.2 g. KNO3, 21.9g. So only KNO3 is less than 25.0 g.
