Answer:
air rises most quikly above water so i'm confuse it's lake or river
Frenkel defect is a defect in crystalline solids in which an atom is displaced from its lattice position to an interstitial space. This creates a vacant space at the original site and an interstitial defect at the new site within the same element. This defect does not affect the chemical properties of the compound. This defect usually occur in ionic solids with large size difference between the anion and cation.
LiCl does not exhibit Frenkel defect because the size difference between the anion and the cation of the compound is very small.
Answer : The final temperature of the solution in the calorimeter is, 
Explanation :
First we have to calculate the heat produced.

where,
= enthalpy change = -44.5 kJ/mol
q = heat released = ?
m = mass of
= 1.52 g
Molar mass of
= 40 g/mol

Now put all the given values in the above formula, we get:


Now we have to calculate the final temperature of solution in the calorimeter.

where,
q = heat produced = 1.691 kJ = 1691 J
m = mass of solution = 1.52 + 35.5 = 37.02 g
c = specific heat capacity of water = 
= initial temperature = 
= final temperature = ?
Now put all the given values in the above formula, we get:


Thus, the final temperature of the solution in the calorimeter is, 
Answer:
Option B is correct = 1,3
Explanation:
Chemical equation:
C₂H₄ + O₂ → CO₂ + H₂O
Balanced chemical equation:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
Step 1:
Left side Right side
C = 2 C = 1
H = 4 O = 3
O = 2 H = 2
Step 2:
C₂H₄ + O₂ → 2CO₂ + H₂O
Left side Right side
C = 2 C = 2
H = 4 O = 5
O = 2 H = 2
Step 3:
C₂H₄ + O₂ → 2CO₂ + 2H₂O
Left side Right side
C = 2 C = 2
H = 4 O = 6
O = 2 H = 4
Step 4:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
Left side Right side
C = 2 C = 2
H = 4 O = 6
O = 6 H = 4