Melting Point of pure ice is-
Melting Point of Pure Ice
The melting point is a specific temperature at which a substance changes its state from solid to liquid. For pure substances, this temperature is constant under standard pressure. Understanding the melting point of pure ice is a fundamental concept in chemistry and physics.
Ice Melting Point in Celsius
The melting point of pure ice is universally known to be 0 degrees Celsius (\(^{\circ}\text{C}\)). This is the temperature at which ice begins to turn into liquid water at standard atmospheric pressure.
Melting Point Conversion to Kelvin
The Kelvin scale is an absolute temperature scale, meaning that 0 K represents absolute zero, the lowest possible temperature. To convert temperatures from Celsius to Kelvin, we use a straightforward formula:
$$\text{Temperature in Kelvin (K) = Temperature in Celsius } (^{\circ}\text{C}) + 273.15$$
However, for general purposes and multiple-choice questions, the value is often approximated to 273.
- Given the melting point of pure ice is \(0^{\circ}\text{C}\).
- Using the conversion formula with the approximation:
- $$\text{Melting Point in Kelvin (K) = } 0^{\circ}\text{C} + 273$$
- $$\text{Melting Point in Kelvin (K) = } 273 \text{ K}$$
Analyzing the Options
Let's examine the given options based on our understanding of the melting point of pure ice:
| Option | Value | Analysis |
|---|---|---|
| 1 | 273 K | This matches the calculated melting point of pure ice when converted from \(0^{\circ}\text{C}\) to Kelvin. This is the correct melting point. |
| 2 | 0 K | 0 K represents absolute zero, the theoretical lowest possible temperature, where all molecular motion ceases. Ice melts at a much higher temperature than 0 K. |
| 3 | -273 K | Temperature cannot be negative on the Kelvin scale as 0 K is the absolute minimum. This value is incorrect. |
| 4 | 300 K | 300 K is approximately \(27^{\circ}\text{C}\) (\(300 - 273 = 27\)), which is room temperature, not the melting point of ice. |
Therefore, based on the conversion from Celsius to Kelvin, the melting point of pure ice is 273 K.
Important Questions from Thermodynamics
- Second law of thermodynamics states that
A. Energy flows from higher concentration to lower concentration.
B. Order becomes disorder during energy transformations.
C. The quality of energy degrades as it is transformed.
D. Degraded energy is entropy, dessipated as waste products or heat.
E. Enthalpy is wasted in energy transformation.
Choose the most appropriate answer from the options given below: Choose the Incorrect Statement:
1 For a system at equilibrium, chemical potential is same in all phases.
2 Gibb's free energy change is zero at equilibrium state of a system.
3 Gibb's free energy change is positive for reaction to occur spontaneously.
4 $\Delta G$ will become more negative with increasing temperature.- In a closed thermodynamic system, across its boundaries
Which one among the following statements with reference to the properties of water is not correct?
For a certain reaction, ΔG θ = -45 kJ/mol and ΔH θ = -90 kJ/mol at 0 °C. What is the minimum temperature at which the reaction will become spontaneous, assuming that ΔH θ and ΔS θ are independent of temperature?
