Answer:There are
6.022×10(to the power of 23)
atoms in 40.0 grams of sodium hydroxide.
Step-by-step explanation:
To find the number of atoms in a given amount of substance, you can use the concept of moles and Avogadro's number. Avogadro's number is approximately
6.022
×
1
0
23
6.022×10
23
atoms/mol.
Find the molar mass of sodium hydroxide (NaOH).
Sodium (Na) has a molar mass of approximately 22.99 g/mol.
Oxygen (O) has a molar mass of approximately 16.00 g/mol.
Hydrogen (H) has a molar mass of approximately 1.01 g/mol.
22.99
g/mol
+
16.00
g/mol
+
1.01
g/mol
=
40.00
g/mol
22.99g/mol+16.00g/mol+1.01g/mol=40.00g/mol.
Calculate the number of moles using the formula:
moles
=
mass
molar mass
=
40.0
g
40.00
g/mol
=
1.00
mol
moles=
molar mass
mass
=
40.00g/mol
40.0g
=1.00mol
Use Avogadro's number to find the number of atoms:
number of atoms
=
moles
×
(
6.022
×
1
0
23
atoms/mol
)
number of atoms=moles×(6.022×10
23
atoms/mol)
number of atoms
=
1.00
mol
×
(
6.022
×
1
0
23
atoms/mol
)
=
6.022
×
1
0
23
number of atoms=1.00mol×(6.022×10
23
atoms/mol)=6.022×10
23