The Physics
Hypertextbook
Opus in profectus

# The Atomic Nature of Matter

## Problems

### practice

1. Verify the following claims about the mole.
1. A mole of dollar bills would make a stack almost 7000 light years high.
2. A mole of mini marshmallows would cover the Earth to a depth of about 1 kilometer.
3. A mole of standard men would weigh about 7 Earth masses.
4. A mole of food calories could feed every person on Earth for about 94 million years.
5. Counting a mole of anything at a rate of one object per second would take about 19 quadrillion years.
2. How many moles of water are in a one liter bottle of water?
3. Write something different.
4. Write something completely different.

### numerical

1. "A spoonful of sugar helps the medicine go down" is how the song goes. Not that I recommend consuming sugar by the spoonful, but how may moles is this? There are many different chemical compounds that are called sugar, but let's assume that this sugar is sucrose (C12H22O11) also known as table sugar. A spoonful is not a precisely defined amount, and measuring bulk material like sugar by volume drives food scientists mad. Let's be nice to these and other food professionals and just say that a spoonful of sugar is some convenient mass — 4 grams.
2. Single acting baking powder is a mixture of tartaric acid (a.k.a. cream of tartar, which has nothing to do with the condiment called tartar sauce) and sodium bicarbonate (a.k.a. baking soda, which has nothing to do with the class of beverages called soda). The two basic compounds are stoichiometrically balanced, which is the technical way to say that there are the same number of moles of each. The number of molecules may be in a ratio of 1:1, but the number of grams is not. Determine the mass ratio of tartaric acid (KC4H5O6) to sodium bicarbonate (NaHCO3) in baking powder.