Question

Help please, I'll love you foreverrrrr! xo

"Paraffin, a wax used to make candles, has a molecular formula of

C25H52 (s) + 38 O2 ---> 23 CO2 (g) + 26 H2O (l)

How many liters of Co2 are produced when a 23.4g paraffin candle burns at STP?"

Answer 1

Convert the mass given to moles (this requires adding up the molar masses of the individual elements - data given on the periodic table).

the formula is: \(\sf moles=\dfrac{mass}{molar~mass}\)

Next you need to use the molar ratio.

\(\color{red}{1}~C_{25}H_{52} (s) + \color{red}{38}~ O_2 ---> \color{red}{23}~ CO_2 (g) + \color{red}{26}~ H_2O (l)\)

Set up a ratio using the species of interest, like so:

e.g. for a general reaction:

\(\color{red}{a}A + \color{blue}{b}B\) \(\rightleftharpoons\) \( \color{green}{c}C\)

where upper case are the species (A,B,C), and lower case (a,b,c) are the coefficients,

\(\dfrac{n_A}{\color{red}{a}}=\dfrac{n_B}{\color{blue}{b}}=\dfrac{n_C}{\color{green}{c}}\)


so for you equation it's: \(\dfrac{n_{CO_2}}{23}=\dfrac{n_{Parafin}}{1}\)

plug in moles (the symbol n), solve for moles of \(CO_2\).

Answer 2

After to convert the moles to Liters of gas, you need to use the ideal gas law, PV=nRT

but for instances where you're at STP, there is a shortcut.

Multiply the moles by 22.414 L, this is the volume of one mole of any gas at STP.