To find the net ionic equation we must first write the balanced equation for the reaction. We must bear in mind that the reagents Ca(NO3)2 and Na2S are in the aqueous state and as product we will have CaS in the solid state, since it is not soluble in water and NaNO3 in the aqueous state.
The balanced equation of the reaction will be:

Ca(NO3)2(aq) + → Ca(aq) + 2Na(s)NO3Now, c(aq)ompounds in the aqueous state can be written in their ionic form, so the reaction will transform into:Na2S +

So, the answer will be option A
ΔG⁰ = ΔH⁰ - T ΔS⁰
ΔG⁰ : Standard free energy of formation of acetylene
ΔH⁰ : Standard enthalpy of formation (226.7 kJ/mol)
ΔS⁰ : Standard entropy change (58.8 J / K. mol)
T : Temperature 25°C = 298 K (room temperature)
ΔG⁰ = 226.7 - (298 x 58.8 x 10⁻³) = 209.2 kJ /mol
Answer: "physical change" .
________________________________________________________
This would be a "physical change" . ________________________________________________________
<u>Note</u>: This would change from a "solid" to a "liquid" / mere rearrangement of molecules/ NOT a new chemical substance—hence, a "physical change".
________________________________________________________
Answer:
Two molecules of hydrogen combine with two molecules of oxygen to form hydrogen peroxide. Hence, its chemical formula is H2O2. It is the simplest peroxide (since it is a compound with an oxygen-oxygen single bond). Hydrogen peroxide has basic uses as an oxidizer, bleaching agent and antiseptic
Answer is: <span>Double Displacement.
Combustion is reaction with oxygen.
</span>Synthesis is reaction of two or more substances combining to make a more complex
substance.
Decomposition is reaction where one substance is broken down into two or more simpler substances.
Single Displacement is reaction where neutral element metal or nonmetal
become an ion as it replaces another ion in a compound.
<span>Double displacement
reactions (more reactive metals displace metals with lower reactivity).
</span>Neutralization<span>is is </span>reaction<span> in which an </span>acid<span> and a </span>base<span> react quantitatively with each other.</span>