True when the boron control rods are lowered it slows the reaction
Answer:The correct answer is option C.
Explanation;
Water has unique property that is, it expands on freezing.Which is the reason for less density of ice than water. The cracking of the bottle was due to the expansion of water (present inside the bottle) on freezing.
Generally, density is inversely proportional to the volume of the substance.


As we know ,that water expands on freezing which means that volume increases. And with increase in volume of density decreases.
Hence, the correct answer is option C.
<u>Answer:</u> The entropy change of the ethyl acetate is 133. J/K
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

Given mass of ethyl acetate = 398 g
Molar mass of ethyl acetate = 88.11 g/mol
Putting values in above equation, we get:

To calculate the entropy change for different phase at same temperature, we use the equation:

where,
= Entropy change = ?
n = moles of ethyl acetate = 4.52 moles
= enthalpy of fusion = 10.5 kJ/mol = 10500 J/mol (Conversion factor: 1 kJ = 1000 J)
T = temperature of the system = ![84.0^oC=[84+273]K=357K](https://tex.z-dn.net/?f=84.0%5EoC%3D%5B84%2B273%5DK%3D357K)
Putting values in above equation, we get:

Hence, the entropy change of the ethyl acetate is 133. J/K
Hey, its alright bro! I gotchu.
Im pretty sure the galactic symbol is the same reference to the symbol of the element on the periodic table.
For an example (Hydrogen) is H
So if im correct im pretty sure its referring to the symbols for each element
Hopefully this helps