Answer:
Its C
Explanation:
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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
Answer:
An F1 offspring could produce four types of gametes, RY, Ry, rY, and ry. The F2 generation supports the independent-assortment model and refutes the linkage model.
Explanation:
<>"The researchers stress that their approach does not offer a complete roadmap for sustainable development, but does provide an important element by identifying critical planetary boundaries. "Human pressure on the Earth system has reached a scale where abrupt global environmental change can no longer be excluded."<>
Answer:
NH₃
M = n/V(L)
0.844 mol (Both numbers have 3 significant figures so the result has 3 significant figures as well)
Explanation:
Step 1: Given and required data
- Volume of solution (V): 375. mL
- Molar concentration of the solution (M): 2.25 M
- Chemical formula for ammonia: NH₃
Step 2: Calculate the moles (n) of ammonia (solute)
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V(L)
n = M × V(L)
n = 2.25 mol/L × 0.375 L = 0.844 mol (Both numbers have 3 significant figures so the result has 3 significant figures as well)
