the mass number of fluorine (F) is 19
C. 19
<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)
The answer is B, Let me know if you get it right!
Answer : The enthalpy of the reaction = -1839.6 KJ
Solution : Given,
= -520.0 KJ/mole
= -1699.8 KJ/mole
The balanced chemical reaction is,

Formula used :


We know that the standard enthalpy of formation of the element is equal to Zero.
Therefore, the enthalpy of formation of (Mn) and (Al) is equal to zero.
Now, put all the values in above formula, we get
![\Delta (H_{f})_{reaction}=[2moles\times (-1699.8 KJ/mole)}+3moles\times (0\text{ KJ/mole}})]-[(3moles\times(-520.0KJ/mole }+4moles\times(0\text{ KJ/mole})]](https://tex.z-dn.net/?f=%5CDelta%20%28H_%7Bf%7D%29_%7Breaction%7D%3D%5B2moles%5Ctimes%20%28-1699.8%20KJ%2Fmole%29%7D%2B3moles%5Ctimes%20%280%5Ctext%7B%20KJ%2Fmole%7D%7D%29%5D-%5B%283moles%5Ctimes%28-520.0KJ%2Fmole%20%7D%2B4moles%5Ctimes%280%5Ctext%7B%20KJ%2Fmole%7D%29%5D)
= (-3399.6) + (1560)
= -1839.6 KJ