Answer:
1.
Explanation:
Hello,
In this case, for the given reaction we first assign the oxidation state for each species:

Whereas the half reactions are:

Next, we exchange the transferred electrons:

Afterwards, we add them to obtain:

By adding and subtracting common terms we obtain:

Finally, by removing the oxidation states we have:

Therefore, the smallest whole-number coefficient for Sn is 1.
Regards.
First, we construct the reaction equation:
Na₂SO₃ + 2HCl → 2NaCl + SO₂ + H₂O
H₂SO₃ is formed as an intermediate but decomposes to water and SO₂ gas.
Answer:
Those two horizontal lines.
Explanation:
Hello there!
In this case, when focusing on these heating curves, it is important to say they tend to have two constant-temperature sections and three variable-temperature sections. Thus, from lower to higher temperature, the first constant-temperature section corresponds to melting and the second one vaporization, whereas the three variable-temperature sections correspond to the heating of the solid until melting, the liquid until vaporization and the gas until the critical point.
In such a way, we infer that the boxes referred to constant temperature are referred to a gain in potential energy, that is, the two horizontal lines.
Regards!