Answer:
I learnt k,l,m
Explanation:
so 1-3periods have klm and after that klmn
Answer:
3). 1.30 × 10^(24) molecules
Explanation:
From avogadro's law which state that equal volume of all gases at the same temperature and pressure contain the same number of molecules.
We can relate it to this question as;
V₁/n₁ = V₂/n₂
Where;
V₁ is initial volume
n₁ is initial number of molecules
V₂ is final volume
n₂ is final number of molecules
Thus at STP, we have V₁ = V₂ and as such Plugging in the relevant values gives;
5/(1.30 x 10^(24)) = 5/n₂
n₂ = 1.30 x 10^(24) molecules
Answer:
13500 N
Explanation:
According to newtons second law of motion
mass m =1500 Kg
a = 9m/s^2
Force F = mass m × acceleration a
F = 1500×9= 13500 N
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
