Seeing signs of a chemical reaction does not always mean that a reaction is happening. For example, a gas (water vapor) is given off when water boils. ... You can tell that it is a physical change because water vapor can condense to form liquid water. In a chemical change, a new substance must be produced.
Your answer would be 0,8856 mol H2O.
Molar mass of H2O is approximately 18 g/mol
15.94/18 = 0,8856 mol H2O
Answer:
0.4912 kJ/K
Explanation:
Using steam table, the properties of water at stage 1 can be determined:
= 400 kPa
= 60°C
Therefore, from steam table:
specific volume 
entropy 
Calculating the specific volume of water after the partition is removed, since the mass is constant and volume of water is doubled:
Final pressure of water in the tank = 
dryness factor after removing the partition
Therefore:
Thus, the entropy change is:
Δs = 
Therefore, the entropy change of water is 0.4912 kJ/K
Answer: Option (b) is the correct answer.
Explanation:
When it rains, then mud in the backyards become wet. It is known that earthworms live inside earth and diffusion of oxygen gets slower through water than through air.
As a result, supply of oxygen to the worms decreases in wet mud hence, they come to the surface in order to breathe.
Thus, we can conclude that wet mud in the backyard most likely formed the earthworms.
