Question

26 grams of 2,2 dimethyl hexane( C8H16) under goes combustion. How

Answer 1

Answer: The $CO_{2}$ gas occupies a space of 5.57 L at 26 Celsius and 101.75 kPa.

Explanation:

Given: Mass = 26 g

Pressure = 101.75 kPa

Convert kPa into atm as follows.

$1 kPa = 0.00986923 atm\\101.75 kPa = 101.75 kPa \times \frac{0.00986923 atm}{1 kPa}\\= 1 atm$

Temperature = $26^{o}C = (26 + 273) K = 299 K$

Now, moles of a substance is defined as mass of substance divided by its molar mass.

As molar mass of 2,2 dimethyl hexane is 114.23 g/mol. So, its number of moles are calculated as follows.

$No. of moles = \frac{mass}{molar mass}\\= \frac{26}{114.23 g/mol}\\= 0.227 mol$

Formula used to calculate the volume is as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

$PV = nRT\\1 atm \times V = 0.227 mol \times 0.0821 L atm/mol K \times 299 K\\V = 5.57 L$

Thus, we can conclude that the $CO_{2}$ gas occupies a space of 5.57 L at 26 Celsius and 101.75 kPa.