Sodium benzoate (c6h5coona), the sodium salt of the weak acid benzoic acid, is used as a food preservative. a solution is prepared by dissolving 0.100 mol of sodium benzoate in enough pure water to produce 1.00 l of solution. if the pka for benzoic acid is 4.20, calculate the ph of the sodium benzoate solution.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

what is the question?

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.