Answer:
C
Explanation:
It is also better so scientists know that the data is accurate and that the results will be reliable. If an investigation is replicable, somebody else can use it. In order for others to achieve the same results scientists also have to be able to collect the same data ...
The energy produced by burning : -32.92 kJ
<h3>Further explanation</h3>
Delta H reaction (ΔH) is the amount of heat change between the system and its environment
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
The enthalpy and heat(energy) can be formulated :

The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol.
The energy released for 0.8210 g of naphthalene :

I believe your answer is 23.
Credit: answers.yahoo.com
Hope this helps!
Answer:
The law of conservation of mass states that mass cannot be created or destroyed only transfered. So when a size change takes place the mass is being transfered into something else. During a state change the mass is being transfered into another state of matter. When a substance dissolves into another liquid the mass is still their just into another state.
Explanation:
I believe you just look at your periodic table for this value. I don't think there is any math involved.
Therefore one mole of Mg = 24.305g.