Answer:
-179.06 kJ
Explanation:
Let's consider the following balanced reaction.
HCl(g) + NaOH(s) ⟶ NaCl(s) + H₂O(l)
We can calculate the standard enthalpy change for the reaction (ΔH°r) using the following expression.
ΔH°r = 1 mol × ΔH°f(NaCl(s)) + 1 mol × ΔH°f(H₂O(l)) - 1 mol × ΔH°f(HCl(g)) - 1 mol × ΔH°f(NaOH(s))
ΔH°r = 1 mol × (-411.15 kJ/mol) + 1 mol × (-285.83 kJ/mol) - 1 mol × (-92.31 kJ/mol) - 1 mol × (-425.61 kJ/mol)
ΔH°r = -179.06 kJ
Answer:
A. CsBr(s)
Explanation:
we will get here compound with the lowest lattice energy
solution
As we know that Lattice energy is always proportional to the charge of ions and it is inversely proportional to the size of ions.
so that by the smallest charge and the largest size give us the lowest lattice energy and that charge and size is express as here as
Charge
Cs (+1), K(+1), Na (+1), Cl(-1), Br(-1), Sr(+2), Ca(+2), O(-2) .......................1
and
Size
Na+ < Ca2+ < K+ < Sr2+ < Cs+, O2- < Cl- < Br- ..........................2
so that here
correct answer is A. CsBr
Answer: balanced chemical equation: 
Net ionic equation :
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The balanced chemical equation is:

Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.
The ions which are present on both the sides of the equation are sodium and nitrate ions and hence are not involved in net ionic equation.
Hence, the net ionic equation is
I think the answer is number (4)
Answer:
Nucleus
Explanation: it is the center of the atom, and contains protons and nuetrons