Cracking the SAT Chemistry Subject Test

true.

24. B To find mass in grams, we need only multiply the isotope mass by
    the number of moles present. 2.5 mol × 2.014 g/mol = 5.035 g. Only (A)
    reflects both the proper calculation AND the right number of significant
    figures.


25. B When NaOH and HCl neutralize, water and NaCl salt are produced.
    After evaporation, the solid will burn yellow (B) in a flame test. (C) and (D)
    are the colors for different metallic salts, while (A) and (E) are very
    unlikely in a standard flame test procedure.