Answer:
active because he built up antibodies due to exposure to the flu
Explanation:
Mass of iron chloride (FeCl₂) : 22.68 g
<h3>Further explanation</h3>
Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
In the same compound, although from different sources and formed by different processes, it will still have the same composition/comparison
With this law, we can calculate how many grams an element is needed to make a compound with a certain mass, as desired
<h3 />

The iron ions in 50 g mixture :


Answer:
copper(ll) carbonate
Explanation:
Since the product is a salt which is copper(II) carbonate, water and carbon dioxide, this reaction is an acid + metal carbonate reaction.
Looking at the salt, Cu²⁺ has to be part of the reactants.
Hence, the missing compound there has to be copper(ll) carbonate, CuCO₃.
The balanced chemical equation would be:
CuCO₃ + 2HNO₃➙ Cu(NO₃)₂ +H₂O +CO₂
P.s. You left out CO₂ as a product in Q2 ;)
Just a recap of the main reactions you would've learnt:
1) Acid + base/ alkali ➙ salt + water
2) Acid + metal ➙ salt + hydrogen gas
3) Acid + metal carbonate ➙ salt + H₂O + CO₂
Answer : The reaction is endothermic in nature.
Explanation : A system of reactants which absorbs heat from the surroundings in an endothermic reaction has a positive ΔH reaction value, as the enthalpy of the products is higher than the enthalpy of the reactants of the system.
As the enthalpies of these reactions are greater than zero, they are called as endothermic reactions. Which absorbs the heat during the chemical reactions.