Calculate a reasonable amount (mass in g) of your unknown acid to use for a titration. You will want about 30 mL of titrant to get to the equivalence point. Assume that your base is about 0.05 M and that your unknown acid has a molar mass around 400 g/mol. (Report your answer using 2 significant figures).

Explanation:

1) from the periodic table for example if u looking for K it is from the group 1A so the valancey = +1 that is mean it loses one electron to reach a stable state. and this applied for the 1A , 2A, 3A groups.

if u looking for N it is from group 5A so its valency is -3

so it gain 3 electrons to reach a stable state to complete its orbital to 8 electrons. this applied to 5A, 6A,7A

for the transition metals and simimetals other rules.

2) neutral if the element does not hold any charge like

H2, O2, N2, Fe, Au, Cu ...

isotope : if the 2 elements have same symbol and atomic number but they differ in the mass number because the have different numbers of neutrons.

if the element is charged then it is considered as an ion ex: Fe2+ then it is iron cation ( +ion)

F- then it is fluoride anion (-ion)

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