Answer:
The atomic number is the number of the elements inside the periodic table and the mass is the weight or a number under the elements.
Explanation:
Correct me if I am wrong
The volume of the gas that occupy at STP is 165. 28 cm^3
calculation
by use of combined gas law that is P1V1/T1=P2V2/T2, where
P1=84.6 kpa
T1=23.5 +273=296.5 K
V1=215 cm^3
At STP T= 273 K and P= 101.325 Kpa
therefore p2 = 101.325 Kpa and T2 = 272 K V2=?
by making V2 the subject of the formula V2 =T2P1V1/P2T1
V2 = 273 K x 84.6 Kpa x 215 cm^3/ 101,.325 Kpa x296.5 K =165.28 cm^3
Definitely C, ability to create delicate flavors. :)
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
1. Relative dating
2. I don't know
3. Absolute dating
4. Absolute dating
I hope this helps...
