When pentane C5H12 is burned in excess oxygen, the products of the reaction are CO2(g) and H2O(l). In the balanced equation for this combustion,C5H12(g) _ O2 (g) → 5CO2(g) + 6H2O(l) the coefficient of the oxygen should be:
Correct answer: D. 8
- A. 16
- B. 12
- C. 11
- D. 8
Explanation
When hydrocarbon reacts with oxygen it forms carbon dioxide and water.C5 H1 2+O2 →CO2 +H2 OStart by using the 5 carbons in the hydrocarbon to form 5 carbon dioxide.Then use the 12 hydrogens to form 6 waters. Then count up the oxygen atoms needed.5×O2 =10O6×O1 =6O = 16There must be 16 oxygens on the left or reactants to balance the equation. So8×O2 =16OHence,1×C5 H12 +8×O2 →5×CO2 +6H2 OThe balanced equation is:C5 H12 +8O2 →5CO2 +6H2 O
Last updated
About Fundamental Concepts of Chemistry
Mole calculations connect mass, number of particles and Avogadro's number, while balanced equations provide the mole ratios used in stoichiometry. Questions cover limiting and excess reactants, theoretical yield and percentage yield, including identifying which reactant is consumed first and comparing the actual product with the maximum possible product.
Practise Fundamental Concepts of Chemistry
894 free Fundamental Concepts of Chemistry MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
0.078 g of hydrocarbon occupies 22.4 ml of volume at 1 atm and 0˚C. The empirical formula of the hydrocarbon is CH. The molecular formula is:
0.36 moles of each aluminum and oxygen react with each other to produce aluminum oxide. The amount of product formed is
0.5 mole of H2O is formed when one gram of H2 react with how many gram of oxygen
0.5 mole of H2O is formed when one gram of H2 react with how many grams of oxygen?
0.5 moles of H₂O are formed when one gram of H₂ reacts with how many grams of oxygen?