Answer: The reaction is exothermic. The value of q is  -542 kJ.
Explanation:
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.
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.
Thus 
 evolves heat , it is exothermic in nature. The value of q is -542kJ.
 
        
             
        
        
        
A: making s sandcastle. This is because water and sand is only a mixture, so they do not react with each other. All the rest include chemical reactions!
        
             
        
        
        
Answer:
Letter B.
Explanation:
Changing its direction and climbing a steep incline can't be proven only by the graph info. You can see that it's speed isn't constant in the graph. 
We have letter B left.
 
        
             
        
        
        
Saturated solution is a solution in which no more solute can be dissolved in the solvent. When saturated solution cools, the solution began precipitate from the solution, because under lower temperature, usually, less amount solute can be dissolved in the solvent.
 
        
                    
             
        
        
        
Answer:
See below  
Step-by-step explanation:
An exothermic reaction tends to occur spontaneously because the products are more stable than the reactants.
Nature tries to get to the lowest energy state.