Answer:
pH is calculated by taking negative logarithm of hydrogen ion concentration. Acids have pH ranging from 1 to 6.9, bases have pH ranging from 7.1 to 14 and neutral solutions have pH equal to 7. Thus the sum of pH and pOH is 14
Explanation:
Explanation:
Adhesion means the ability to stick on the surface of another substance.
Water exhibits adhesive forces due to which it is able to stick to the glass. Due to adhesive forces water spreads over the surface of glass and sticks to it.
These adhesive forces between the glass and water enough that it deforms the spherical shape of water molecules and help them stick to the surface of glass. As a result, adhesive forces overcome the repulsion between like molecules.
Hence, water is able to “stick” to the side of glass due to strong adhesive forces.
Conduction: In the conduction, the heat is transferred from the hotter body to the colder body until the temperature on both bodies are equal.
In thermal equilibrium, there is no heat transfer as the heat is transferred till the temperature on the bodies are not same.
In the given problem, an iron bar at 200°C is placed in thermal contact with an identical iron bar at 120°C in an isolated system. After 30 minutes, the thermal equilibrium is attained. Then, the temperature on both iron bars are equal.Both iron bars are at 160°C in an isolated system.
But in an open system, the temperatures of the iron bars after 30 minutes would be less than 160°C. There will be heat lost to the surrounding. The room temperature is 25°C. There will be exchange of the heat occur between the iron bars and the surrounding. But It would take more than 30 minutes for both iron bars to reach 160°C because heat would be transferred less efficiently.
Less friction to stop the wheel from turning
