Answer: Ice is melting due to the transfer of thermal energy from Jan's hand to ice.
Explanation: The melting of ice is a physical change and is happening when the thermal energy from Jan's hand is transferred to ice. Due to this energy transfer, the particles of ice starts to move faster and hence, making the ice melt.
In this, the physical state of ice is changing from solid to liquid state.
The mathematical expression for heat capacity at constant pressure is given as:
(1)
where, Q = heat capacity
= molar heat capacity at constant pressure
= change in temperature
n = number of moles
Therefore, =
=
Number of moles =
=
= 0.186 mole
Put the values in formula (1)
(conversion of degree Celsius into kelvin)
=
= 6.32 J /mol K
Hence, molar heat capacity of benzene at constant pressure =
According to law of conservation of mass, mass can neither be destroyed nor created in a chemical reaction. Thus, sum of masses of reactants must be equal to sum of masses of products in a reaction.
The chemical reaction is as follows:
Here, sum of masses of Cu and oxygen gas should be equal to CuO formed.
Thus, mass of oxygen will be:
This can be further proved as follows:
The balanced chemical reaction is as follows:
Here, 2 moles of Cu completely reacts with 1 mole of to give 2 moles of
.
Thus, 1 mole of Cu reacts with 0.5 moles of .
The mass of Cu is 508.4 and molar mass is 63.546 g/mol, number of moles can be calculated as follows:
Thus, number of moles of reacting will be:
Molar mass of oxygen molecule is 32 g/mol thus, mass can be calculated as follows:
m=n×M=4 mol×32 g/mol=128 g/mol
This satisfies the law of conservation of mass.