Ice float on water. Which hydrogen bond is responsible for this? Intermolecular hydrogen bond or intramolecular hydrogen bond.
Simple answer is that the density of ice that is 0.9 g/cm³ is less that density of water that is 1 g/cm³.
Now if you ask, why density of ice is lesser than water, you need to know about hydrogen bonds. HYDROGEN BOND is the electrostatic force of attraction between hydrogen (which is already in a molecule) and a highly electronegative atom nearby. In water, H Bonds occur between oxygen and hydrogen.
At 0°C, inter molecular hydrogen bonds exist in ice, unbroken in form of a tetrahedral structure . Increasing the temperature above 0°C, hydrogen bonds start to break and tetrahedral structure starts to collapse and H20 molecules fill up the space. So when more molecules are gathering at one place, volume decreases and hence density increases. This continue till 4°C. Above 4°C ,hydrogen bonds break frequently but the decrease in volume caused by breaking of H Bonds is less than the increase in volume caused due to expansion of water (heating causes expansion). Hence, density of ice is less than water. *density of water highest at 4°C.
Simple answer is that the density of ice that is 0.9 g/cm³ is less that density of water that is 1 g/cm³.
Now if you ask, why density of ice is lesser than water, you need to know about hydrogen bonds. HYDROGEN BOND is the electrostatic force of attraction between hydrogen (which is already in a molecule) and a highly electronegative atom nearby. In water, H Bonds occur between oxygen and hydrogen.
At 0°C, inter molecular hydrogen bonds exist in ice, unbroken in form of a tetrahedral structure . Increasing the temperature above 0°C, hydrogen bonds start to break and tetrahedral structure starts to collapse and H20 molecules fill up the space. So when more molecules are gathering at one place, volume decreases and hence density increases. This continue till 4°C. Above 4°C ,hydrogen bonds break frequently but the decrease in volume caused by breaking of H Bonds is less than the increase in volume caused due to expansion of water (heating causes expansion). Hence, density of ice is less than water. *density of water highest at 4°C.
