Question 1

What is the valency of each carbon atom in an ethylene molecule?

Accepted Answer

Each carbon atom in an ethylene molecule has four valence electrons and forms four single covalent bonds, making the valency of each carbon atom four. Choice B is the correct answer.

Question 2

If the bond angles at a carbon atom are 180°, then how many groups are distributed around the carbon atom?

Accepted Answer

A carbon atom with bond angles of 180° is involved in sp hybridization, which means it is bonded to two other atoms, forming a linear shape.

Question 3

If the bond angles at a carbon atom are 120°, then how many groups are distributed around the carbon atom?

Accepted Answer

A bond angle of 120° indicates a trigonal planar geometry, meaning there are three groups (or atoms) distributed around the carbon atom.

Question 4

Which of the following is a property of most organic compounds?

Accepted Answer

None of these choices are a property of most organic compounds. Organic compounds can exist in various states of matter (solid, liquid, or gas) and may or may not be soluble in water depending on their chemical structure.

Question 5

Which of the following chemicals in its pure natural form will have properties different from its pure synthetic form?

Accepted Answer

The properties of a chemical compound are determined by its molecular structure, not by its source. Therefore, ethanol, Taxol, and vitamin C will have the same properties whether they are produced synthetically or extracted from natural sources.

Question 6

Which of the following statements about organic chemistry is false?

Accepted Answer

This statement is false because organic compounds can be synthesized in the laboratory through various methods, including chemical reactions and biological processes.

Question 7

The chemical formula of methylamine is CH₃NH₂. How many valence electrons are associated with a molecule of methylamine?

Accepted Answer

Methylamine has the chemical formula CH3NH2. Counting the valence electrons: Carbon (C) has 4, each Hydrogen (H) has 1 (and there are 3 H atoms in the methyl group and 2 H atoms bonded to N), and Nitrogen (N) has 5. Adding these gives 4 (from C) + 3*1 (from the 3 H in the methyl group) + 2*1 (from the 2 H bonded to N) + 5 (from N) = 14 valence electrons.

Question 8

Which of the following is true of organic compounds?

Accepted Answer

Organic compounds, which are primarily made up of carbon atoms bonded to hydrogen, oxygen, and other elements, tend to have lower melting points than inorganic compounds. This characteristic makes them more likely to be gases, liquids, or solids that melt at lower temperatures.

Question 9

In organic compounds, which of the following elements forms two covalent bonds and has two unshared pairs of electrons?

Accepted Answer

Oxygen forms two covalent bonds and has two unshared pairs of electrons in organic compounds. Carbon forms four covalent bonds, hydrogen forms one covalent bond, and nitrogen forms three covalent bonds.

Question 10

How do inorganic compounds differ from organic compounds?

Accepted Answer

Inorganic compounds typically contain ions that can conduct electricity in their aqueous solutions, whereas organic compounds do not contain ions and cannot conduct electricity in their aqueous solutions. The other options provided are not true of all inorganic or organic compounds, so they do not distinguish between the two types.

Question 11

In organic compounds, which of the following elements forms three covalent bonds and has one unshared pair of electrons?

Accepted Answer

Nitrogen forms three covalent bonds and has one unshared pair of electrons, making it a common element in organic compounds such as amino acids and nucleic acids.

Question 12

Which of the following statements about Taxol is false?

Accepted Answer

Taxol and paclitaxel are the same drug, and the terms are used interchangeably.

Question 13

A chemist has two pure samples of an organic compound, one of which is obtained from a natural source and one of which is synthesized in the laboratory. Which of the following properties can be used to identify the synthetic sample?

Accepted Answer

None of these properties can be used to definitively identify the synthetic sample. Both natural and synthetic samples of the same compound can have the same boiling point, formula weight, and solubility, so these properties alone cannot distinguish between them. Other analytical techniques, such as spectroscopy, would be required for identification.

Question 14

Which element accounts for the largest percentage of the Earth's crust?

Accepted Answer

Oxygen is the most abundant element in the Earth's crust, making up about 46.6% of its weight.

Question 15

Which of the following statements about Taxol is false?

Accepted Answer

All the statements provided about Taxol are true. Taxol, a compound obtained from the bark of the yew tree, is indeed available in very small quantities from natural sources, requiring the bark of a 100-year-old tree for just about 1 gram of Taxol. It is used effectively in the treatment of certain types of ovarian and breast cancers. Additionally, synthetic versions of Taxol have been developed to mimic the properties of naturally obtained Taxol, making the statement about their properties being the same also true.

Question 16

Which of the following statements is generally true of most organic compounds?

Accepted Answer

Organic compounds are characterized by covalent bonding, which involves the sharing of electrons between atoms. This type of bonding is prevalent in organic compounds, which are primarily composed of carbon atoms bonded to other carbon atoms or to atoms of other elements like hydrogen, oxygen, and nitrogen. Additionally, because of the covalent bonding, organic compounds do not typically dissociate into ions in solution. Therefore, their aqueous solutions do not conduct electricity well, distinguishing them from ionic compounds, which do dissociate into ions in solution and conduct electricity.

Question 17

Which of the following statements regarding urea is incorrect?

Accepted Answer

Urea is not a protein made up of two amino acids. It is a small organic molecule that contains a carbonyl group attached to two amino groups.

Question 18

If the bond angles at a carbon atom are 109.5°, then how many groups are distributed around the carbon atom?

Accepted Answer

A carbon atom with bond angles of 109.5° is sp3 hybridized, indicating it is bonded to four groups, forming a tetrahedral geometry.

Question 19

Which of the following statements is true of organic compounds?

Accepted Answer

Natural gas, petroleum, and coal are all fossil fuels derived from the remains of once-living organisms, making them natural sources of organic compounds. Option A is incorrect because some organic compounds can be synthetically produced. Option B is incorrect because the boiling point of a compound is not determined solely by whether it is natural or synthetic. Option C is incorrect because Valium, Zoloft, and Prozac are all synthetic pharmaceutical drugs.

Question 20

What is the bond angle at the carbon atom of a methane molecule?

Accepted Answer

The bond angle at the carbon atom of a methane molecule is tetrahedral, which is approximately 109.5 degrees. Option C is the only choice with this value.

Quiz 10: Organic Chemistry

What is the valency of each carbon atom in an ethylene molecule?

If the bond angles at a carbon atom are 180°, then how many groups are distributed around the carbon atom?

If the bond angles at a carbon atom are 120°, then how many groups are distributed around the carbon atom?

Which of the following is a property of most organic compounds?

Which of the following chemicals in its pure natural form will have properties different from its pure synthetic form?

Which of the following statements about organic chemistry is false?

The chemical formula of methylamine is CH3NH2. How many valence electrons are associated with a molecule of methylamine?

Which of the following is true of organic compounds?

In organic compounds, which of the following elements forms two covalent bonds and has two unshared pairs of electrons?

How do inorganic compounds differ from organic compounds?

In organic compounds, which of the following elements forms three covalent bonds and has one unshared pair of electrons?

Which of the following statements about Taxol is false?

A chemist has two pure samples of an organic compound, one of which is obtained from a natural source and one of which is synthesized in the laboratory. Which of the following properties can be used to identify the synthetic sample?

Which element accounts for the largest percentage of the Earth's crust?

Which of the following statements about Taxol is false?

Which of the following statements is generally true of most organic compounds?

Which of the following statements regarding urea is incorrect?

If the bond angles at a carbon atom are 109.5°, then how many groups are distributed around the carbon atom?

Which of the following statements is true of organic compounds?

What is the bond angle at the carbon atom of a methane molecule?

The chemical formula of methylamine is CH₃NH₂. How many valence electrons are associated with a molecule of methylamine?