Answer: During a phase change, such as melting or boiling, the kinetic energy increases.
Explanation:
Kinetic energy is the energy obtained by the molecules of a substance due to their motion.
When phase change such as melting or boiling takes place then it means heat is absorbed by the substance. As a result, their molecules more even more rapidly from one place to another due to which more number of collisions take place.
Hence, a change in phase of substance occurs as kinetic energy increases in melting or boiling process.
Thus, we can conclude that during a phase change, such as melting or boiling, the kinetic energy increases.
Answer:
0.40 L
Explanation:
Calculation of the moles of
as:-
Mass = 51.24 g
Molar mass of
= 171.34 g/mol
The formula for the calculation of moles is shown below:
Thus,

Volume = 1.20 L
The expression for the molarity is:


Thus,
Considering
Given that:
So,
<u>The volume of 0.24925M stock solution added = 0.40 L
</u>
Using the relative atomic weights of both copper and sulfur ie copper = 63.55 and sulfur is 32.06 so 63.55+32.06=95.56 total mass and so of this, copper = 63.55/95.56=66.4%. So to get 10 grams of copper, use the formula 10g=66.4%xCuS so CuS=10/0.664=15.06 grams of CuS.