How much hydrogen (in liters at STP) is required to change 857 kg of diisobutylene to isooctane? Molar mass of diisobutylene is 112.2 grams. CH₃C(CH₃)₂CH=C(CH₃)₂ + H₂ → CH₃C(CH₃)₂CH₂CH(CH₃)₂

Question

Quizplus · Accepted Answer

First, we need to calculate the number of moles of diisobutylene.
857 kg of diisobutylene = 857000 g / 112.2 g/mol = 7646.17 mol
According to the balanced chemical equation, one mole of diisobutylene reacts with one mole of hydrogen to produce one mole of isooctane.
So, we need 7646.17 mol of hydrogen.
Now we can use the ideal gas law to calculate the volume of hydrogen at STP (standard temperature and pressure).
PV = nRT
STP conditions: 
P = 1 atm 
V = ? 
n = 7646.17 mol 
R = 0.08206 L•atm/mol•K 
T = 273.15 K 
Solving for V: 
V = (nRT)/P 
V = (7646.17 mol)(0.08206 L•atm/mol•K)(273.15 K)/(1 atm) 
V = 1.71 × 10^5 L or 1.71 × 10^15 mL or 1.71 × 10^12 cm^3 
Converting to liters and rounding to two significant figures, we get 1.7 × 10^15 L which is equivalent to 1.71 × 10^15 L. Therefore, the answer is B) 1.71 × 10^15 L.

How Much Hydrogen (In Liters at STP) Is Required to Change