Answer:
i guess its example of observation 
 
        
             
        
        
        
Answer:
 = 25.05°C
 = 25.05°C
Explanation:
Given:
the value of ΔHcomb (heat of combustion) for dimethylphthalate (C10H10O4) is = 4685 kJ/mol. 
mass = 0.905g of dimethylphthalate
molar mass = 194.18g dimethylphthalate
number of moles of dimethylphthalate = ???
 = 21.5°C
 = 21.5°C
 = 6.15 kJ/°C
 = 6.15 kJ/°C
 = ???
 = ???
since we have our molar mass and mass of dimethylphthalate ;we can determine the number of moles as;
0.905g of dimethylphthalate ×  
 number of moles of dimethylphthalate = 0.000466 moles
Heat released = moles of dimethylphthalate × heat of combustion
=  0.000466 moles × 4685 kJ
= 21.84 kJ
∴ Heat absorbed by the calorimeter =   
 
21.84 kJ =6.15 kJ/°C 
21.84 KJ = 
21.84 KJ =  - 132.225 kJ
 - 132.225 kJ
21.84 KJ + 132.225 kJ = 
154.065 kJ = 
 =
 = 
 =25.05°C
 =25.05°C
 
        
             
        
        
        
Answer:
1,31÷2 =10,11
Explanation:
c10h22+31÷2o2=10co2+11h2o
 
        
             
        
        
        
D milk turning sour 
the other options are physical changes