Question

1.-Using octane C8H18 as fuel in combustion with an excess of 10% of theoretical air. Calculate the heat released if air enters the combustion process at 25°C and gases exit the combustion chamber at 327°C.

120

likes
598 views

Answer to a math question 1.-Using octane C8H18 as fuel in combustion with an excess of 10% of theoretical air. Calculate the heat released if air enters the combustion process at 25°C and gases exit the combustion chamber at 327°C.

Expert avatar
Birdie
4.5
99 Answers
1. **Balanced Combustion Equation with Theoretical Air:**

- Combustion of octane:
C_8H_{18} + 12.5 O_2 \rightarrow 8 CO_2 + 9 H_2O

- With theoretical air:
C_8H_{18} + 12.5 O_2 + 12.5 \left(\frac{79}{21} N_2\right) \rightarrow 8 CO_2 + 9 H_2O + 12.5 \left(\frac{79}{21} N_2\right)

2. **Combustion with 10% Excess Air:**

- Total air with 10% excess:
\text{Total air} = 1.1 \times \text{theoretical air}

- Updated equation:
C_8H_{18} + 1.1 \times 12.5 \left(O_2 + \frac{79}{21} N_2\right) \rightarrow 8 CO_2 + 9 H_2O + 1.1 \times 12.5 \left(\frac{79}{21} N_2\right) + 0.1 \times 12.5 O_2

3. **Calculate the Heat Released:**

- Enthalpy of Combustion:
\text{LHV of octane} = 44,740 \, \text{kJ/kg}

- Molecular weight of octane:
114.23 \, \text{g/mol}

- Heat released per mole:
\text{Heat released per mole} = 44,740 \, \text{kJ/kg} \times \frac{114.23 \, \text{g/mol}}{1000 \, \text{g/kg}} = 5112.7 \, \text{kJ/mol}

4. **Heat Change Due to Exit Temperature:**

- \( Q = \Delta H = H_\text{enter} - H_\text{exit} \)

- Assuming minor variations of heat capacity, results in:
Q = 5112.7 \, \text{kJ/mol}

The heat released from the combustion of octane with 10% excess air, with the given conditions, is approximately **5112.7 kJ per mole** of octane.

Frequently asked questions (FAQs)
How many tickets were sold for the concert if the total revenue was $20,000 and each ticket cost $80?
+
What is the length of the perpendicular bisector of a triangle if two sides are given as 6 cm and 8 cm?
+
Question: Find the area of a triangle with side lengths 5, 6, and 9, using Heron's formula?
+
New questions in Mathematics
Solution to the equation y'' - y' - 6y = 0
a ferry travels 1/6 of the distance between two ports in 3/7 hour. the ferry travels at a constant rate. at this rate, what fraction of the distance between the two ports can the ferry travel in one hour?
A circular park has a diameter of 150ft. A circular fence is to be placed on the edge of this park. Calculate the cost of fencing this park if the rate charged is $7 per foot. Use π = 3.14.
1/2x +3 <4x-7
two particles start at the origin and move along the x axis. for 0 <= t <= 10, their respective position functions are given by x1 = cos(t) and x2 = (e^-3t) + 1. for how many values of t do the particles have the same velocity?
How many percent is one second out a 24 hour?
Which of the following is the product of multiplying twenty-seven and twenty-five hundredths by nine and twenty-seven hundredths?
To celebrate the five-year anniversary of a consultancy specializing in information technology, the administrator decided to draw 3 different qualification courses among its 10 employees. Considering that the same employee cannot be drawn more than once, the total number of different ways of drawing among employees is:
2x2 and how much?
4x/2+5x-3/6=7/8-1/4-x
suppose random variable x follows poisson distribution with expected value 3. what is variance of x?
Let x be an integer. Prove that x^2 is even if and only if is divisible by 4.
48 kg of 30% sulfuric acid in a mixture of 10% and 40% sulfuric acid arose. How many kilograms were each of the original solutions?
When taking a test with m closed answers, a student knows the correct answer with probability p, otherwise he chooses one of the possible answers at random. What is the probability that the student knows the correct answer given that he answered the question correctly.
A post office has three categories of letters: 60% are from businesses, 30% are individual mail, and the remaining 10% are government mail. 5% of the letters from businesses have address errors, 10% of the individual mail has address errors, while 1% of the government mail has address errors. If we receive a letter with an address error, what is the probability that it is individual mail?"
Marc, Jean and Michelle have traveled a lot. Marc drove twice as much as Jean, but it was Michelle who drove the most with 100km more than Marc. They respected their objective of not exceeding 1350km of distance. How far did John drive?
Sodium 38.15 38.78 38.5 38.65 38.79 38.89 38.57 38.59 38.59 38.8 38.63 38.43 38.56 38.46 38.79 38.42 38.74 39.12 38.5 38.42 38.57 38.37 38.71 38.71 38.4 38.56 38.39 38.34 39.04 38.8 A supplier of bottled mineral water claims that his supply of water has an average sodium content of 36.6 mg/L. The boxplot below is of the sodium contents levels taken from a random sample of 30 bottles. With this data investigate the claim using SPSS to apply the appropriate test. Download the data and transfer it into SPSS. Check that your data transfer has been successful by obtaining the Std. Error of the mean for your data which should appear in SPSS output as 0.03900.. If you do not have this exact value, then you may have not transferred your data from the Excel file to SPSS correctly. Do not continue with the test until your value agrees as otherwise you may not have correct answers. Unless otherwise directed you should report all numeric values to the accuracy displayed in the SPSS output that is supplied when your data has been transferred correctly. In the following questions, all statistical tests should be carried out at the 0.05 significance level. Sample mean and median Complete the following concerning the mean and median of the data. mean =  mg/L 95% CI:  to  mg/L Based upon the 95% confidence interval, is it plausible that the average sodium content is 36.9 mg/L?      median:  mg/L The median value is      36.9 mg/L. Skewness Complete the following concerning the skewness of the data. Skewness statistic =        Std. Error =  The absolute value of the skewness statistic     less than 2 x Std. Error Therefore the data can be considered to come from a population that is      . Normality test Complete the following summary concerning the formal testing of the normality of the data. H0: The data come from a population that     normal H1: The data come from a population that     normal Application of the Shapiro-Wilk test indicated that the normality assumption     reasonable for sodium content (S-W(  )=  , p=   ). Main test Using the guidelines you have been taught that consider sample size, skewness and normality, choose and report the appropriate main test from the following ( Appropriate ONE ) You have selected that you wish to report the one-sample t-test. H0: The mean sodium content     equal to 36.9 mg/L H1: The mean sodium content     equal to 36.9 mg/L Application of the one-sample t-test indicated that the mean is      36.9 mg/L (t(  ) =  , p =   ). You have selected that you wish to report the Wilcoxon signed rank test. H0: The median sodium content     equal to 36.9 mg/L H1: The median sodium content     equal to 36.9 mg/L Application of the Wilcoxon signed rank test indicated that the median is      36.9 mg/L (z =  , N =  , p =   ).
A candy manufacturer must monitor deviations in the amount of sugar in their products They want their products to meet standards. They selected a random sample of 20 candies and found that the sandard deviation of that sample is 1.7. What is the probabilty of finding a sample variance as high or higher if the population variance is actually 3277 Assume the population distribution is normal.
An export company grants a bonus of $100,000 pesos to distribute among three of its best employees, so that the first receives double the second and the latter receives triple the third. How much did each person receive?
f(r) = 1/r+9 find f(x^2) + 1