Answer:
c. HF can participate in hydrogen bonding.
Explanation:
<u>The boiling points of substances  often reflect the strength of the </u><u>intermolecular forces</u><u> operating among the molecules.</u>
If it takes more energy to  separate molecules of HF than of the rest of the hydrogen halides because HF molecules are held  together by stronger intermolecular forces, then the boiling point of HF will be higher than  that of all the hydrogen halides.
A particularly strong  type of intermolecular attraction is called the hydrogen bond, <em>which is a special type of dipole-dipole interaction between the hydrogen atom in a polar bond</em>, such as N-H, O-H, or F-H, and an electronegative O, N, or F atom.
 
        
             
        
        
        
Answer:
the chemical equation of ethanol as fuel is
C2H5OH(l)+3 02(g)------2CO2(g)+3H2O(g)
the preparation process of ethanol from cassava is
cassava flour---liquification---saccharification---cooling---fermentation---distillation---ethanol
 
        
             
        
        
        
If you think of it endothermic is when there is energy needed for the reaction to occur and exothermic is when the reaction releases energy
        
             
        
        
        
Explanation:
The speed of molecules increases when temperature is increased as it will result in more number of collisions between the molecules. Thus, there will be  increase in kinetic energy of molecules and increase in the speed of solvent molecules.
Whereas on decreasing the temperature, the kinetic energy of molecules will decrease. This will result in less number of collisions between the molecules. Therefore, the speed of solvent molecules will slow down.
 
        
             
        
        
        
B. both high energy and low energy waves