Question

The density of lead is 11.4 g/cm3 at 20°C. A chemist has a metallic sample that is either pure lead or mostly lead. If the density of the sample is 11.0 g/cm3 at 20°C, then the sample most likely is _____.  
A. pure lead 
b. lead mixed with heavier substances 
c. lead mixed with lighter substances

Answer 1

Answer:

The correct answer is option c.

Explanation:

Density is defined as mass present in unit volume of the substance.

$Density=\frac{Mass}{Volume}$

Given that density of pure lead is more than that of the sample.

Density of lead = $11.4 g/cm^3$

Density of sample = $11.0 g/cm^3$

Since, we know that density is directly linked to mass of the substance. So with decrease in density of substance indicates that mass present in unit volume of the substance has also decreased.

The reason behind the less density of sample from lead was that, that it was made up lead and other light substance.

Answer 2

The sample is most likely lead with lighter substances in it. Pure lead would be closer to the pure lead density, and heavier substances would make the density more, not less.