CHEM 120 EXAM 2 INTRODUCTION TO GENERAL ORGANIC AND BIOLOGICAL CHEMISTRY NEW UPDATE CERTIFICATION REVIEW SET 2026 QUESTIONS WITH ANSWERS GRADED A+

CHEM 120 EXAM 2 INTRODUCTION TO
GENERAL ORGANIC AND BIOLOGICAL
CHEMISTRY NEW UPDATE CERTIFICATION
REVIEW SET 2026 QUESTIONS WITH
ANSWERS GRADED A+

⫸ Avogadro's Number Answer: 6.02 x 10^23


⫸ molar mass Answer: the mass in grams of one mole of a substance


⫸ moles to grams Answer: moles x molar mass


⫸ grams to moles Answer: grams/molar mass


⫸ percent composition Answer: the percent by mass of each element in
a compound


⫸ empirical fomula Answer: simplest whole number ration in which
kinds of atoms combine to form a compound


⫸ percent composition to empirical formula Answer: mass percent<-
>convert to grams and divide by molar mass<->moles of each element<-
>divide by smallest number of moles<->moles of ratio of elements<-
>change to integer subscripts<->empirical formula

, ⫸ molecular formula Answer: A chemical formula that shows the
number and kinds of atoms in a molecule, but not the arrangement of the
atoms.


⫸ molecular formula from percent composition and molar mass
Answer:


⫸ The unit of molarity is ______/______ Answer: moles/liter


⫸ How to calculate concentration Answer: concentration =
(amount/volume)(moles/L)


⫸ How to calculate dilutions Answer: (concentration1 x volume 1) =
(concentration2 x volume2)


⫸ mass % Answer: mass of solute/mass of solution x 100


⫸ volume % Answer: volume of solute/volume of solution x 100


⫸ parts per million by mass (ppm) Answer: mass of solute/mass of
solution x 10^6


⫸ Parts per billion by mass (ppb) Answer: mass of solute/mass of
solution x 10^9