Answer:
[tex]\boxed {\boxed {\sf 856.74 \ g \ C_8H _{18}}}[/tex]
Explanation:
To convert from grams to moles, the molar mass is used. These values tells us the grams in 1 mole of a substance. They can be found on the Periodic Table (they are equivalent to the atomic masses, but the units are grams per mole).
We are given the compound C₈H₁₈. Look up the molar masses of the individual elements.
Notice there are subscripts that tell us the number of atoms of each element. We must multiply the molar masses by the subscripts.
Add these 2 values together to find the molar mass of the whole compound.
Use this number as a ratio.
[tex]\frac{ 114.232 \ g \ C_8H_{18}}{1 \ mol \ C_8H_{18}}[/tex]
Multiply by the given number of moles: 7.5
[tex]7.5 \ mol \ C_8H_{18}*\frac{ 114.232 \ g \ C_8H_{18}}{1 \ mol \ C_8H_{18}}[/tex]
The moles of C₈H₁₈ will cancel each other out.
[tex]7.5 *\frac{ 114.232 \ g \ C_8H_{18}}{1}[/tex]
[tex]7.5 *{ 114.232 \ g \ C_8H_{18}}[/tex]
[tex]856.74 \ g \ C_8H _{18}[/tex]
7.5 moles of C₈H₁₈ is equal to 856.74 grams of C₈H₁₈