Answer: Endothermic reaction
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
As the energy of reactants is 180 kJ and that of products is 300 kJ, the energy of products is greater than that of reactants, which means the energy has been absorbed and reaction is endothermic.
Sorry, Cant really tell how to differentiate the students and trial times
Answer:
(II) only correctly rank the bonds in terms of increasing polarity.
Explanation:
Bond polarity is proportional to difference in electronegativity between bonded atoms.
Atoms Electronegativity Bond Electronegativity difference
Cl 3.0 Cl-F 1.0
Br 2.8 Br-Cl 0.2
F 4.0 Cl-Cl 0
H 2.1 H-C 0.4
C 2.5 H-N 0.9
N 3.0 H-O 1.4
O 3.5 Br-F 1.2
I 2.7 I-F 1.3
Si 1.9 Cl-F 1.0
P 2.2 Si-Cl 1.1
Si-P 0.3
Si-C 0.6
Si-F 2.1
So, clearly, order of increasing polarity : O-H > N-H > C-H
So, (II) only correctly rank the bonds in terms of increasing polarity
Answer:
In the calorimeter, water is the <u>exothermic</u>. The salt LiCI, which will dissolve, is the <u>endothermic</u>. The final temperature of the water after the dissolution of LiCI was <u>lower</u> than the initial temperature, meaning the process is <u>exothermic</u>. In the microscopic view of the disspolution of LiCI, water molecules were seen to move <u>slowly</u> as they <u>gained </u>energy.
Explanation:
Exothermic is a process in which heat is released during the process. Endothermic reactions absorbs heat from surrounding during a chemical process. The dissolution of salt into water is an exothermic reaction. During this process heat is release and water molecules are broken down which are surrounded by salt ions.
