Answer:
lead ii nitrate is the answer
Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.
Correct Question:
A chemist measures the enthalpy change ΔH during the following reaction: Fe(s) + 2HCl(g)-->FeCl2(s) + H2 ΔH=-157.0 kJ. Use this information to complete the table below. Round each of your answers to the nearest kJ/mol
Answer:
-314 kJ
+628 kJ
+157 kJ
Explanation:
The enthalpy change of a reaction measures the amount of heat that is lost or gained by it. If ΔH >0 the heat is gained, and the reaction is called endothermic, if ΔH<0, the heat is lost, and the reaction is called exothermic.
If the reaction is inverted, the value of ΔH is inverted too (the opposite endothermic reaction is exothermic), and if the reaction is multiplied by a constant, ΔH will be multiplied by it too.
1) 2Fe(s) + 4HCl --> 2FeCl2(s) + 2H2(g)
This reaction is the product of the given reaction by 2, so
ΔH = 2*(-157) = -314 kJ
2) 4FeCl2(s) + 4H2(g) --> 4Fe(s) + 8HCl(g)
This reaction is the inverted reaction given multiplied by 4, so
ΔH = 4*(157) = +628 kJ
3) FeCl2(s) + H2(g) --> Fe(s) + 2HCl
This reaction is the inverted reaction given, so
ΔH = +157 kJ
<span>The number next to the simbol of the element ions (as a superscript) means the number of charges of the ion. For example N (+),, where (+) is a superscript means that the charge of the ion is 1+. S(2-), where (2-) is a superscript, means that the charge of the ion is (2-). OH (-), where (-) is a superscript, means that the charge of OH ion is (1-) . </span>
Inside the stomach, Hydrochloric acid kills micro-organisms in the food. Stomach juices begin to break down <u>proteins</u> to amino acids.
✤ So, Fill the blank with proteins.
<h3>
<u>Explanation:-</u></h3>
- Inside the stomach, the digestion of proteins starts due to the action of pepsin enzyme.
- But this enzyme remains inactive and is activated by the Hydrochloric acid(HCl).
- The Hydrochloric acid also helps in killing the germs and microbes which entered along with food.
- The mucous lines the wall of stomach to protect it from the harm caused by HCl because HCl is a strong acid.
- In stomach, The partial digestion of proteins occur and rest is digested in the small intestine by Trypsin(Pancreatic enzyme) and Intestinal juices.
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