The answer is number 4 or the exchange of energy with the surroundings. Calorimetry is a measurement of energy that is formed or absorbed in a certain process. The calorimeter is the instrument used in order to measure the energy. It is recommended that a calorimeter should be a closed system so as to measure precisely the energy and avoid or lessen the exchange of energy with the surroundings. Thus, comparing an open ceramic mug and an insulated mug with a lid, the greatest difference is the energy lost to the surroundings.
Answer: The number to the left of AC should be 6.
Explanation: The balanced chemical reaction is one in which the number of atoms of each element on the reactant side must be equal to the number of atoms on product side.
The given equation
is unbalanced as the atoms on the reactant side are not same as number of atoms on product side. This equation is called as skeletal equation.
The balanced chemical equation is :

Thus the number to the left of AC is 6.
In order to become a scientific theory the three
categories that it must pass are the following:
1) Can the phenomena be recreated in a laboratory setting?
2) Can variables be changed, yet still result in like observations?
3) Is the phenomena truly natural or was it the result of a man-made force
enacting upon it?
Answer:
Q sln = 75.165 J
Explanation:
a constant pressure calorimeter:
∴ m sln = m Ba(OH)2 + m HCl
∴ molar mass Ba(OH)2 = 171.34 g/mol
∴ mol Ba(OH)2 = (0.06 L)(0.3 mol/L) = 0.018 mol
⇒ mass Ba(OH)2 = (0.018 mol)(171.34 g/mol) = 3.084 g
∴ molar mass HCl = 36.46 g/mol
∴ mol HCl = (0.06 L)(0.60 mol/L) = 0.036 mol
⇒ mass HCl = (0.036 mol)(36.46 g/mol) = 1.313 g
⇒ m sln = 3.084 g + 1.313 g = 4.3966 g
specific heat (C):
∴ C sln = C H2O = 4.18 J/g°C
∴ ΔT = 26.83°C - 22.74°C = 4.09°C
heat absorbed (Q):
⇒ Q sln = (4.3966 g)(4.18 J/g°C)(4.09°C)
⇒ Q sln = 75.165 J