FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 4: The Mole and Stoichiometry

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 51

Multiple Choice

Review LaterAdd Note

Review Later

A 6.789 g sample of a hydrocarbon, upon combustion analysis, yielded 9.883 grams of carbon dioxide. What is the percent, by mass, of carbon in the hydrocarbon?

A) 18.75 %
B) 39.73 %
C) 68.69 %
D) 45.57 %
E) 34.44 %

F) B) and E)
G) C) and E)

Correct Answer

verified

Show Answer

Question 52

Multiple Choice

Review LaterAdd Note

Review Later

In a quantitative analysis study, 4.624 grams of a hydrocarbon compound yielded 13.84 g of CO₂ and 7.556 g of H₂O in a combustion analysis apparatus. Determine the empirical formula of the compound. Hint: Use moles to relate the quantities of the substances.

A) CH₃
B) C₂H₅
C) C₃H₈
D) C₁₀H₂₆
E) C₁₀H₂₇

F) B) and E)
G) None of the above

Correct Answer

verified

Show Answer

Question 53

Short Answer

Review LaterAdd Note

Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4NH₃ + 5O₂ → 4NO + 6H₂O When 20.0 g NH₃ and 50.0 g O₂ are allowed to react, which is the limiting reagent?

The atomic mass of cobalt is 58.933 u. How many moles of Co are there in a 7.60 g sample of cobalt?

Select the correct balanced chemical equation for the reaction below. C₆H₁₄ + O₂ $\rarr$ CO₂ + H₂O

There are ________ moles of oxygen atoms in 25.7 g of CaSO₄.

The atomic mass of cobalt is 58.993 u. What is the mass of a cobalt sample that contains 0.763 moles of cobalt?

In the course of determination of a chemical formula, a student obtained the following mole ratios: The empirical formula for the compound is ________.

What is the percent, by mass, of tungsten in W(CH₃) ₆?

How many moles of carbon atoms are combined with 11.2 moles of hydrogen atoms in a sample of the compound, C₃H₈?

A 4.626 g sample of a hydrocarbon, upon combustion analysis, yielded 6.484 grams of carbon dioxide. What is the percent, by mass, of carbon in the hydrocarbon? Hint: Use moles to relate the quantities of the two substances.

A compound contains sodium, boron, and oxygen. An experimental analysis gave values of 53.976 % sodium and 8.461 % boron, by weight; the remainder of the mass is oxygen. What is the empirical formula of the compound? Hint: Assume you have 100 grams of this substance and use moles to relate the mass of one element to another.

An average atom of uranium (U)is approximately how many times heavier than an atom of phosphorus?

How many moles of carbon atoms are in 0.145 moles of the compound, C₃H₈?

In combustion analysis, a hydrocarbon compound undergoes complete combustion in excess oxygen to produce a stream of gases. The stream of gases passes through a pre-weighed tube. The increase in mass of these tubes represents the combined mass of CO₂ and H₂O. The mass of the element ________ in the hydrocarbon can be directly calculated from the mass of H₂O.

In a chemical reaction, the best yield currently obtainable in any process is 99.5%.

There are ________ moles of oxygen atoms in 10 moles of KClO₃.

A compound contains arsenic and oxygen as its only elements. A 1.626 g sample of the compound contains 1.232 g of arsenic. What is the empirical formula of the compound?

When the equation is balanced, Al₂O₃ + C → Al + CO₂, the coefficient for CO₂ is ________.

When octane (C₈H₁₈)is burned in a particular internal combustion engine, the yield of products (carbon dioxide and water)is 93%. What mass of carbon dioxide will be produced in this engine when 15.0 g of octane is burned with 15.0 g of oxygen gas?