Question

Three identical vessels A, B, and C are filled with water, mercury, and kerosene respectively up to an equal height. The three vessels are provided with identical taps at the bottom of the vessels. If the three taps are opened simultaneously, then which vessel is emptied first?
A) Vessel B
B) All the vessels A, B, and C will be emptied simultaneously.
C) Vessel A
D) Vessel C

Answer 1

The density of a liquid is the measure of the number of particles in the given amount of space. Density is a characteristic of a liquid.in hydrocarbon density of the liquid depends on the intermolecular force of attraction. Density increases with the increase in the carbon chain. However, kerosene is a mixture of 10 different hydrocarbons which includes straight-chain, branched-chain, and cycloparaffin hydrocarbons. This decreases the density of kerosene.

Complete step by step answer:
Density is defined as the ratio of mass per unit volume. In other words, it is the amount of substance in the given amount of space. Mathematically it is written as,
$\text{ Density = }\frac{\text{mass}}{\text{Volume}}\text{ }$
Hydrocarbons are composed of carbon and hydrogen. Saturated carbons have a maximum number of hydrogen atoms linked to carbon atoms. The physical properties of alkanes depend on intermolecular forces of interaction between the molecules. As the length of the carbon chain increases the intermolecular forces of attraction that are Van der Waals forces of attraction increase. Thus with an increase in the carbon chain, the substance becomes denser.
Density is related to the viscosity of the solution. A decrease in the density of viscosity decreases the viscosity of liquid and thus increases the free-flowing characteristic of a liquid.
Kerosene is also known as paraffin or lamp oil. It is a combustible hydrocarbon and it is derived from petroleum. Kerosene has a low viscosity. Kerosene is composed of carbon chains that typically contain 10 and 16 carbon atoms per molecule. It typically contains the 10 different hydrocarbons in it which are straight-chain and branched-chain as well as ring-shaped cycloparaffin (like naphthalene). Thus kerosene has a low density. It has a density equal to $\text{ 0}\text{.78}-\text{0}\text{.81 g / c}{{\text{m}}^{\text{3}}}\text{ }$.
Water has a density approximately equal to $\text{ 1 g / C}{{\text{m}}^{\text{3}}}\text{ }$. Density of water is explained based on the mass of water (1 gram) dissolved per unit volume. Water is taken as a reference substance compared to the solids and liquids.
Mercury is a liquid metal. It is a d-block element. The mercury has a dense core and the mass of an atom is concentrated at the nucleus. Therefore the density of mercury is $\text{ 13}\text{.6 g / C}{{\text{m}}^{\text{3}}}\text{ }$. Thus mercury is highly dense liquid than water and kerosene. It has less free-flowing properties and thus high viscosity.
We can say that the liquid which has less density has less viscosity. Thus it has free-flowing properties. Therefore container C containing kerosene would be emptied first followed by the water container A and at last mercury container B.

Hence, (D) is the correct option.

Note: Note that, there is no direct relationship between the viscosity and the density. But both physical properties are affected by the temperature. With an increase in temperature, the particles start to move and attain the kinematic or motion viscosity which brings down the density of the solution. Thus we can say that when temperature increases, the density of liquid decreases, and this fluid becomes less viscous and flower.