Question

3b practice: chemistry for biology! write out your responses on 3b. include enough detail in your responses so that you know what question you were answering. 1. the chemical formula for palmitic acid (palm oil) is c₁₆h₃₂o₂. a. how many different elements are in this molecule? b. how many atoms of hydrogen are in this molecule? c. how many total atoms are in one molecule of this compound? 2. the chemical formula sodium bicarbonate (baking soda) is nahco₃. a. how many different elements are in this molecule? what are their names? b. how many atoms of hydrogen are in this molecule? c. how many total atoms are in one molecule of this compound? 3. this is an example of a chemical equation. fe is the chemical symbol for iron, o is oxygen, and fe₂o₃ is known as iron oxide, or rust. 4 fe + 3 o₂ → 2 fe₂o₃ a. how would this equation read in words? b. how many iron oxide molecules are on the product side of this equation? c. how many atoms of oxygen are on the product side of this equation? d. how many atoms of oxygen are on the reactant side of the equation? e. how many molecules of oxygen gas are on the reactant side of the equation?

Explanation:

1. For palmitic acid ($C_{16}H_{32}O_2$):

a. Count elements

The elements are carbon (C), hydrogen (H), and oxygen (O). So there are 3 different elements.

b. Find hydrogen atoms

The sub - script of H is 32, so there are 32 hydrogen atoms.

c. Calculate total atoms

Add sub - scripts: $16 + 32+2=50$ total atoms.

2. For sodium bicarbonate ($NaHCO_3$):

a. Count elements and name them

The elements are sodium (Na), hydrogen (H), carbon (C), and oxygen (O), so 4 different elements.

b. Find hydrogen atoms

The sub - script of H is 1, so there is 1 hydrogen atom.

c. Calculate total atoms

Add sub - scripts: $1 + 1+1 + 3=6$ total atoms.

3. For the chemical equation $4Fe + 3O_2

ightarrow2Fe_2O_3$:

a. Write in words

Four atoms of iron react with three molecules of oxygen gas to produce two molecules of iron(III) oxide.

b. Find iron oxide molecules on product side

The coefficient of $Fe_2O_3$ is 2, so there are 2 iron oxide molecules.

c. Find oxygen atoms on product side

In one $Fe_2O_3$ molecule, there are 3 oxygen atoms. Since there are 2 $Fe_2O_3$ molecules, $2\times3 = 6$ oxygen atoms.

d. Find oxygen atoms on reactant side

In one $O_2$ molecule, there are 2 oxygen atoms. Since there are 3 $O_2$ molecules, $3\times2=6$ oxygen atoms.

e. Find oxygen gas molecules on reactant side

The coefficient of $O_2$ is 3, so there are 3 oxygen gas molecules.

Answer:

1.
a. 3
b. 32
c. 50
2.
a. 4 (sodium, hydrogen, carbon, oxygen)
b. 1
c. 6
3.
a. Four atoms of iron react with three molecules of oxygen gas to produce two molecules of iron(III) oxide.
b. 2
c. 6
d. 6
e. 3