I don't know about 14, but 15 is (4), because a liquid draws in heat to turn into a gas. 16 is (2), because to turn into a cold solid, something has to release heat.
1) The balanced chemical equation will be :
<span> 2HClO4 (aq) + Ca(OH)2(aq) → Ca(ClO4)2 (aq) + 2H2O (l)
</span>
Ionic equation:
<span> 2H+(aq) + 2ClO4-(aq) +Ca2+(aq) + 2OH-(aq) → Ca2+(aq) + 2ClO4-(aq) +2H2O(l)
</span>
<span> Net ionic equation: </span>
<span> 2H+ (aq) + 2OH-(aq) → 2H2O(l)
</span>
2) <span>Molecular equation: </span>
<span> H2SO4(aq) + Li2SO3(aq) → Li2SO4(aq) + SO2(g) + H2O(l) </span>
<span>
Ionic equation: </span>
<span> 2H+ (aq) + SO4 2-(aq) + 2Li+ (aq) + SO3 2-(aq) → 2Li+(aq) + SO4 2-(aq) + SO2(g) + H2O(l)
</span>
<span> Net ionic equation: </span>
<span> 2H+(aq) + SO3 2-(aq) → SO2(g) + H2O(l)</span>
Answer:
≈29.94 [°C].
Explanation:
all the details are in the attachment, the answer is underlined with orange colour.
The density of water is a physical property.
You can measure it without changing the water to a different substance.
It is <em>not a physical change</em> because the water does not change to ice or steam.
You can observe a <em>chemical property</em> or a <em>chemical change</em> only if the water <em>changes to a different substance</em>.
