The key difference between water and ice is that the water has no regular arrangement of molecules whereas the ice has a certain crystalline structure.
From the initial stages of the earth’s evolution, water has been a major part of the earth. As for today, water covers more than 70% of the earth’ surface. From this, a larger portion of water is in the oceans and seas; which is about 97%. Rivers, lakes and ponds have 0.6% of water, and about 2% is there in polar ice caps and glaciers. Some amount of water is present in the underground and a minute amount is in the gas form as vapours and in clouds. Among this, there is less than 1% of water left for direct human use. This pure water is also getting polluted day by day, and there should be a proper plan to conserve water.
CONTENTS
1. Overview and Key Difference
2. What is Water
3. What is Ice
4. Side by Side Comparison – Water vs Ice in Tabular Form
5. Summary
What is Water?
Water is an inorganic compound having the chemical formula H2O. Water is something we cannot live without. Two hydrogens covalently bond with an oxygen atom to form a water molecule. Moreover, the molecule gets a bent shape to minimize the electron lone pair-bond repulsion, and the H-O-H angle is 104o. Water is a clear, colourless, tasteless, odourless liquid. Furthermore, it can be in various forms such as mist, dew, snow, ice, vapour, etc. It goes to the gas phase when heats above 100 oC at the normal atmospheric pressure.
Water is truly a wonder molecule. It is the most abundant inorganic compound in living matter. More than 75% of our body composes of water. There, it is a component of cells, act as a solvent and reactant. However, it is a liquid at room temperature, although it has a low molecular weight of 18 gmol-1.
Figure 01: Water is in the Liquid Phase
The ability of water to form hydrogen bonds is a unique characteristic it has. There, a single water molecule can form four hydrogen bonds. Oxygen is more electronegative than hydrogen, making the O-H bonds in water molecule polar. Because of the polarity and the ability to form hydrogen bonds, water is a powerful solvent. Moreover, we call it a universal solvent due to its capability in dissolving a large number of materials. Further, water has a high surface tension, high adhesive, cohesive forces. It can withstand temperature changes without going to the gas or solid form. We name this as having a high heat capacity, which in turn is important for the survival of living organisms.
What is Ice?
Ice is the solid form of water. When we call water below 0oC it starts to freeze forming ice. Ice is either transparent or slightly opaque. However, sometimes it has a colour depending on the impurities it contains. Further, this compound has an ordered regular crystalline structure.
Figure 02: Ice Floats on Water
The hydrogen bonds are important for making this ordered solid structure in ice. The hydrogen bonds keep the H2O molecules with a certain distance from each other, forming a crystalline structure. During this process, the volume of the same mass of H2O expands (which means the mass of water gets comparatively a high volume when freezing to form ice). Since the volume of water expands when it freezes, the density of ice is lower than water. Therefore, it can float on water. This prevents the water in bottoms of the water bodies from freezing at winter period, thus protect aquatic life.
What is the Difference Between Water and Ice?
Ice is the solid form of water, and it has a certain crystalline structure, but water does not have such a regular arrangement of molecules. So, this is the key difference between water and ice. Here, this difference arises due to the presence of hydrogen bonds between the water molecules. During the freezing process, the hydrogen bonds hold the H2O molecules at a certain distance from each other, giving a crystalline structure to ice. Also, this process increases the volume. Therefore, as another important difference between water and ice, we can say that ice has a low density compared to water. Hence it can float on water.
Also, we can identify a difference between water and ice based on their volume and density too. That is; for the same mass, the volume of water is comparatively lower than ice. Because, the density of water is higher than that of ice. The below infographic on difference between water and ice shows more differences between both.
Summary – Water vs Ice
Ice is the solid form of water. However, due to the presence of hydrogen bonds between the water molecules, ice forms with a regular arrangement of H2O molecules when we cool below 0oC. Therefore, the key difference between water and ice is that the water has no regular arrangement of molecules whereas the ice has a certain crystalline structure.
Reference:
1. “Ice, Water, and Simple Chemistry.” Quatr.us Study Guides, Publisher Name Quatr.us Study Guides Publisher Logo, 17 Apr. 2018. Available here
2. Zumdahl, Steven S. “Water.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 4 Oct. 2018. Available here
Image Courtesy:
1.”Water drop impact on a water-surface – (2)”By Davide Restivo from Aarau, Switzerland – Drops #3, (CC BY-SA 2.0) via Commons Wikimedia
2.”Water and ice”By Victor Blacus – Own work, (CC BY-SA 4.0) via Commons Wikimedia