Question 1

Approximately how many new organic compounds are reported each year?

Accepted Answer

B

Question 2

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

Accepted Answer

Oxygen accounts for the largest percentage of the Earth's crust, making up about 46.6% by weight.

Question 3

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

Accepted Answer

A bond angle of 180° indicates a linear geometry, which occurs when there are two groups distributed around the carbon atom.

Question 4

Which of the following statements about organic compounds is true?

Accepted Answer

The number of synthetic organic compounds is much larger than the number of naturally occurring organic compounds due to the vast array of synthetic processes and applications in industries like pharmaceuticals and materials science.

Question 5

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 6

Chemicals in which of the following groups are not considered organic chemicals?

Accepted Answer

Organic chemicals are defined as chemicals that contain carbon and hydrogen atoms bonded together. Enzymes, proteins, and vitamins are all organic compounds because they contain carbon and hydrogen atoms in their structure. Minerals, however, are inorganic compounds as they do not contain carbon-hydrogen bonds.

Question 7

Which of the following is generally true of organic compounds?

Accepted Answer

Generally, organic compounds are not high melting solids and are not soluble in water.

Question 8

Which of the following statements about taxol is false?

Accepted Answer

All the statements provided about taxol are true. Taxol is indeed effective in treating certain cancers, and the synthetic version is identical to the natural one. The yield from a 100-year-old tree is also accurately described.

Question 9

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

Accepted Answer

A bond angle of 120° is indicative of a trigonal planar arrangement, which means there are three groups (or atoms) distributed around the central carbon atom. Therefore, the correct answer is C.

Question 10

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

Accepted Answer

Most organic compounds have covalent bonding, where electrons are shared between atoms, as opposed to ionic bonding where electrons are transferred from one atom to another. However, organic compounds typically do not conduct electricity in their aqueous solutions, as they do not dissociate into ions to carry electrical charge.

Question 11

Which of the following statements is false?

Accepted Answer

Organic compounds can be synthesized in the laboratory using various synthetic methods.

Question 12

In organic compounds, which of the following elements normally forms two covalent bonds?

Accepted Answer

Oxygen typically forms two covalent bonds in organic compounds, as it has six valence electrons and needs two more to complete its octet.

Question 13

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

Accepted Answer

Both natural and synthetic samples of the same compound will have identical physical and chemical properties, such as boiling point, formula weight, and solubility, because they are the same substance. Therefore, none of these properties can be used to distinguish between the two samples.

Question 14

Which of the following is true of organic compounds?

Accepted Answer

Organic compounds are typically gases, liquids, or low melting point solids. Option B is incorrect because organic compounds make up a large majority of all known compounds.

Question 15

The bond angles around the carbon atom in methane (CH₄) are all:

Accepted Answer

Methane has a tetrahedral shape with four identical C-H bonds, and the bond angles in a tetrahedral shape are approximately 109.5 degrees. Therefore, the correct answer is choice C.

Question 16

Which of the following chemicals, when pure, will have different properties if it is synthesized in the laboratory than if it is obtained from a natural source?

Accepted Answer

The chemical properties of a compound are determined by its molecular structure, not its source. Therefore, a pure chemical compound will have the same properties regardless of whether it is synthesized in the laboratory or obtained from a natural source.

Question 17

Which of the following statements about taxol is false?

Accepted Answer

Taxol and paclitaxel are actually the same compound; "Taxol" is the brand name, while "paclitaxel" is the generic name.

Question 18

In organic compounds, which of the following elements normally forms three covalent bonds?

Accepted Answer

Nitrogen typically forms three covalent bonds in organic compounds, as it has five valence electrons and needs three more to complete its octet.

Question 19

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

Accepted Answer

A bond angle of 109.5° indicates a tetrahedral geometry, which means there are four groups distributed around the carbon atom.

Question 20

Which of the following geometries is never associated with a carbon atom in an organic compound?

Accepted Answer

Square planar geometry is never associated with a carbon atom in an organic compound. Carbon typically adopts tetrahedral or trigonal planar geometries due to its bonding properties. Linear geometry may be observed in certain simple molecules, but is not commonly associated with carbon in organic compounds.

Quiz 10: Organic Chemistry

Approximately how many new organic compounds are reported each year?

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

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

Which of the following statements about organic compounds is true?

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

Chemicals in which of the following groups are not considered organic chemicals?

Which of the following is generally true of organic compounds?

Which of the following statements about taxol is false?

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

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

Which of the following statements is false?

In organic compounds, which of the following elements normally forms two covalent bonds?

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

Which of the following is true of organic compounds?

The bond angles around the carbon atom in methane (CH4) are all:

Which of the following chemicals, when pure, will have different properties if it is synthesized in the laboratory than if it is obtained from a natural source?

Which of the following statements about taxol is false?

In organic compounds, which of the following elements normally forms three covalent bonds?

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

Which of the following geometries is never associated with a carbon atom in an organic compound?

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

The bond angles around the carbon atom in methane (CH₄) are all: