The mass of NaCl sample has been 24.3 g. Thus, option A is correct.
The heat of fusion has been the amount of heat required to convert 1 mole of substance into solid to liquid state.
The heat required has been given as:

<h3>Computation for the mass of NaCl</h3>
The given solution has heat of fusion, 
The heat required to melt the sample has been, 
Substituting the values for the mass of NaCl

The mass of NaCl sample has been 24.3 g. Thus, option A is correct.
Learn more about heat of fusion, here:
brainly.com/question/87248
Mass C₆H₈O₇ : 0.531484 g
<h3>Further explanation</h3>
Reaction
3NaHCO₃ (aq) + C₆H₈O₇ (aq) → 3 CO₂ (g) + 3 H₂O (l) + Na₃C₆H₅O₇ (aq)
MW NaHCO₃ : 84 g/mol
mass NaHCO₃ : 7.10² mg=0.7 g
mol NaHCO₃ :

mol C₆H₈O₇ :

MW C₆H₈O₇ : 192 g/mol
mass C₆H₈O₇ :

False. Electromagnetic and Gravitational forces can overcome .
All compounds are molecules because a molecule is 2 or more substances/elements combined and a compound is 2 or more elements combined. But not all molecules are elements because some molecules are just combined substances with no elements combined at all.
Answer:
There are multiple ways to check mass but I'll tell you one. Look below
Explanation:
One easy way of checking atomic mass is by adding protons and neutrons.
For example:
We have 5 protons and 4 neutrons.
5+4=9
I hope this helps (: