I think it would be option 4?
Concentration can be expressed in different forms: molarity, molality, normality, percentage, part per million and many more. For molality, it is a unit of concentration expressed as moles of solute per kilogram of solvent. Therefore,
0.3 = moles solute/0.10 kg solvent
moles solute = 0.03 moles
A system that releases heat to the surroundings, an exothermic reaction, has a negative ΔH by convention, because the enthalpy of the products is lower than the enthalpy of the reactants of the system. The enthalpies of these reactions are less than zero, and are therefore exothermic reactions
<h3><u>Answer;</u></h3>
Step 1; NaHCO3(s) + CH3COOH(l)
Step 2 ; CO2(g)
<h3><u>Explanation;</u></h3>
- The chemical equation for the reaction of baking soda (sodium bicarbonate, NaHCO3) and vinegar (acetic acid, CH3COOH) reaction occurs in two steps.
Step 1;
- A double displacement reaction in which acetic acid in the vinegar reacts with sodium bicarbonate to form sodium acetate and carbonic acid:
- Equation;
NaHCO3(s)+ CH3COOH(l) → CH3COONa(aq) + H2CO3(l)
Step 2;
- Carbonic acid is unstable and undergoes a decomposition reaction to produce the carbon dioxide gas:
H2CO3(l) → H2O(l) + CO2(g)
Answer:
is the value of the equilibrium constant at this temperature.
Explanation:
Equilibrium constant in terms of partial pressure is defined as the ratio of partial pressures of products to the partial pressures of reactants each raised to the power equal to their stoichiometric ratios. It is expressed as 

Partial pressures at equilibrium:



The equilibrium constant in terms of pressures is given as:


is the value of the equilibrium constant at this temperature.