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Molar mass of sodium chloride is 22.99 g/mol (Na+) + 35.45 g/mol (Cl-) = x g/mol. Then take the mass of sodium chloride sample 5 grams and divide by molar mass to get the number of moles. Take this number and multiply it by Avogadro’s number (6.22*10^23 molecules/mol). You now have the amount of molecules in 5 grams of NaCl.
Blue litmus paper turns red in the presence of an acid. Therefore, it can be assumed that the substance in the beaker is an acid.
Acids have a pH level of less than 7. Consequently, it can be assumed that the substance has a pH level less than 7.
What exactly is the question