Answer:
first one is a second one is e
Explanation:
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
Lettuce
Vegetable.
Leaf lettuce.
Head lettuce.
Romaine lettuce.
Asparagus lettuce
38.46g
Explanation:
Given parameters:
Mass of CaF₂ = 75.0g
Unknown:
Mass of calcium that can be recovered = ?
Solution:
This is a mass percentage problem and we need to solve it accordingly.
To solve this problem;
Find the molar mass of CaF₂
Find the ratio between the molar mass of Ca and that of CaF₂
Multiply by the given mass
Molar mass of CaF₂ = 40 + (2 x 19) = 78g/mol
Mass of calcium = 
x 75 = 38.46g
learn more:
Mass percentage brainly.com/question/8170905
#learnwithBrainly
Answer: D
Explanation:
In an inverse relationship as one increases one decreases or vice versa.
