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.
Answer:
C) the energy transferred between objects t different temperatures
Answer:
0.4M NaOH
Explanation:
Molarity, M, is an unit of concentration widely used defined as the ratio between moles of solute (In this case, NaOH) and volume of solution in liters.
As the solution contains 2 moles of NaOH-Moles of solute- in 5L of solution, the molarity is:
2 moles NaOH / 5L =
<h3>0.4M NaOH</h3>