Answer: A. Exothermic reaction
Explanation: Enthalpy change for a reaction is sum of enthalpy of formation of products minus sum of enthalpy of formation of reactants.
When the energy level of reactants is above as compared to the products, the reaction is exothermic and when its opposite then reaction is endothermic.
From given information, the potential energy diagram starts at 380 kJ means the energy level of reactants is 380 kJ. It ends at 100 kJ means the energy of products is 100 kJ.
Enthalpy of reaction = 100 kJ - 380 kJ
Enthalpy of reaction = -280 kJ
Negative sign of enthalpy change indicates an Exothermic reaction.
I have attached the picture ot the H<span>aworth structure of glucose.
You can count in total 6 carbon atoms but only 5 are in the ring portion of the structure.
Therefore, the answer is 5.
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When sulfur reacts with zinc metal is forms a compound known as zinc sulfide.
<h3>
Name of the elements</h3>
The names of the elements that make up the compound will be determined from the atomic mass of the elements.
<h3>Which element has atomic number 30</h3>
The element that atomic number of 30 is zinc and it has oxidation number of +2.
<h3>Which element has atomic number 16</h3>
The element that atomic number of 16 is sulfur and it has oxidation number of -2.
<h3>Chemical reaction between sulfur and zinc metal</h3>
Zn²⁺ + S²⁻ --------> ZnS
Thus, when sulfur reacts with zinc metal is forms a compound known as zinc sulfide.
Learn more about zinc sulfide here: brainly.com/question/20806552
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Answer:
14.68 moles of He
Explanation:
To do this, just remember Avogadro's Constant or Avogadro's number. This constant tells us how many units ( in this case atoms) there are in a mole of ANY type of substance.
Avogadro's constant is 6.022140857 × 10²³ units per mole.
Now that we know how many atoms there are in 1 mole, we can use this as our conversion factor.
8.84 x 10²⁴ atoms of He → moles of He
So the answer would be:
14.68 moles of He
