Answer:
the entropy change for the surroundings when 1.68 moles of Fe2O3(s) react at standard conditions = 49.73 J/K.
Explanation:
3Fe2O3(s) + H2(g)-----------2Fe3O4(s) + H2O(g)
∆S°rxn = n x sum of ∆S° products - n x sum of ∆S° reactants
∆S°rxn = [2x∆S°Fe3O4(s) + ∆S°H2O(g)] - [3x∆S°Fe2O3(s) + ∆S°H2(g)]
∆S°rxn = [(2x146.44)+(188.72)] - [(3x87.40)+(130.59)] J/K
∆S°rxn = (481.6 - 392.79) J/K =88.81J/K.
For 3 moles of Fe2O3 react, ∆S° =88.81 J/K,
then for 1.68 moles Fe2O3 react, ∆S° = (1.68 mol x 88.81 J/K)/(3 mol) = 49.73 J/K the entropy change for the surroundings when 1.68 moles of Fe2O3(s) react at standard conditions.
This problem is providing the mass of both magnesium metal and oxygen gas and involved in a chemical reaction and asks for the limiting reactant. At the end, it turns out to be identified as magnesium.
<h3>Stoichiometry</h3>
In chemistry, stoichiometry is a widely-used tool we use in order to relate the mass and moles of different chemical substances involved in a chemical reaction. Thus, we consider the following chemical equation between magnesium and oxygen to produce magnesium oxide.

However, when the mass of the both of the reactants is given, one must identify the limiting reactant as the one producing the least of the moles of the product, which means we can use the given grams of the both of the reactants, their molar masses and mole ratios with the product to obtain the aforementioned:

Thus, we can evidence how 24 g of magnesium produce the least of the moles of magnesium oxide, fact validating the magnesium as the limiting reactant and the oxygen as the excess one.
Learn more about stoichiometry: brainly.com/question/9743981
4.) D
10.) C
12.) D
13.) D
14.) D
15.) D
In my opinion yes, as of now, almost anyone could get there hands on lets say an explosive. Have you heard of dynamite fishing? It is illegal, but it is still done once people have access to dynamite, then what ends up happening not only do marine wildlife get killed but it pollutes the water and lessens the chance of the natural cycle of life. Also there are several other factors, firstly, what will you do with an explosive once you get your hands on it? Perhaps you could just use an explosive for fun/personal entertainment...that isn't right and it could harm people. So, to conclude the harder it is for people to access explosives or even acclerants the better...and to add this can be possible by making people get like some sort of licence to use them, and let them be trained in certain conditions so that there is no regrets once they have access to them. I know my idea sounds far fetched but its a thought!
Answer:
Solar panels and solar cells.
Explanation:
The word "solar" means "relating to or denoting energy derived from the sun's rays".
Hope this helps! :)