Sodium in Water
A piece of ice melts and reacts with sodium. Is this a physical or chemical change, or both? Explain your answer in the description section

A. Physical change
B. Chemical change
C. Both

C. Both

Explanation:

It is both physical and chemical change. Melting of ice is a physical change and reaction with sodium is chemical change. Initially ice will melt and form water which will react with sodium metal and produce sodium hydrooxide and releases hydrogen gas. This can be explained as follows

2Na(s) + 2H2O → 2NaOH(aq) + H2(g)

Principally, ice would not react with metal however, some of ice would have a little fraction of water molecules which is already melted. This would react with sodium metal. The reaction is exothermic and it will make more ice to melt. Finally, a chain reaction would take place and it will explode because sodium would get too much hot. This is not a physical

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.