If the temperature rises in a reaction. Exothermic is if it loses heat. 
Have a nice day, brainliest would be fantastic.
        
             
        
        
        
Answer:
                       252.68 K   or   -20.46 °C
Explanation:
                     According to Gay-Lussac's Law, "Pressure and Temperature at given volume are directly proportional to each other".
Mathematically,
                                               P₁ / T₁  =  P₂ / T₂   ---- (1)
Data Given:
                   P₁  =  30.7 kPa
                   T₁  =  0.00 °C  =  273.15 K
                   P₂  =  28.4 kPa
                   T₂  =  <u>???</u>
Solving equation for T₂,
                   T₂  =  P₂ T₁ / P₁
Putting values,
                   T₂  =  28.4 kPa × 273.15 K / 30.7 kPa
                   T₂  =  252.68 K   or   -20.46 °C
 
        
             
        
        
        
Answer:
2Cu2^+ + 2I^- ----> 2Cu^+ + I2
Explanation:
The reaction performed in the experiment is;
2 Cu(NO3)2 + 4 KI → 2 CuI (s) + 4 KNO3 + I2
The iodide ions reduces Cu^2+ to Cu^+ which is insoluble in water hence the precipitate. This is so because iodine is a good oxidizing agent seeing that it requires one electron to fill its outermost shell. Potassium on the other hand is a good reducing agent since it easily looses its one electron.
The oxidation - reduction equation is as follows;
2Cu2^+ + 2e ----> 2Cu^+ reduction half equation
2I^- ----> I2 + 2e. Oxidation half equation
Balanced redox reaction equation;
2Cu2^+ + 2I^- ----> 2Cu^+ + I2
 
        
             
        
        
        
Answer:
See explaination 
Explanation:
Reaction between p- toluidine and o- vaniline to form imine.This reaction does occur in the presence of a acidic source.
Here the -OH group in the o- vaniline is quite acidic so it acts a internal acidic catalyst. Hence the reaction occurred in the absence of any external acidic source.The reaction mechanism is given at the attached file.
please kindly see attachment. 
 
        
             
        
        
        
The sun generates its energy by nuclear fusion of hydrogen nuclei into helium.