Class 2 HW - Chemical Bonds

The ability of atoms to attract electrons is referred to as:

electronegativity

A pair of atoms joined by a polar covalent bond:

has a slight positive charge on one atom and a slight negative charge on the other

In aqueous solutions, which type of bond or force has similar bond strength as ionic bond interactions?

hydrogen bonds

Water molecules have high cohesion. This is because between water molecules there are:

hydrogen bonds

A young girl is staring at the raindrops running down her window. She notices that the raindrops remain more or less intact, even as they cascade down the window pane. This is a result of:

hydrogen bonds between water molecules

Fill in the blanks: polar covalent bonds allow ___ substances to interact with water.

hydrophilic

Water readily dissolves compounds that are referred to as

hydrophilic

Which bonds rely on the attraction of positive and negative charges?

ionic and hydrogen bonds

Which functional group contains only nonpolar covalent bonds?

methyl

Which functional group typically has a negative charge at the pH of the cell?

phosphate

The oxygen and hydrogens of a water molecule contains what type of bond:

polar covalent

The unique properties of water are due to the ___ of water molecules and the ability to form ___ with other water molecules and with other polar molecules.

polarity; hydrogen bonds

What is required for ionic bond interactions to form?

opposite full charges

Which statement accurately describes a polar covalent bond?

the unequal sharing of electrons between an atom with a partial positive charge and an atom with a partial negative charge

Of the given types of bonds between atoms, which is the strongest? (van der Waals forces, hydrogen bond, covalent bond, or ionic bond?)

covalent

A pair of shared valence electrons is referred to as a(n):

covalent bond

Which are the strongest bonds in an aqueous environment (surrounded by water) as found in biological systems?

covalent bonds

Because of hydrogen bonding, water is uniquely suited for its central role in life. Many hydrophilic molecules interact freely with water, but a number of hydrophobic molecules are important for life, too. How does this interaction between water and hydrophobic molecules help to organize biological systems?

Because water molecules preferentially associate with each other, they force hydrophobic molecules to associate with each other and not with water molecules.

Recalling that a carbon atom possesses 4 valence electrons, what is the most likely structural formula for carbon dioxide (CO2)?

O=C=O

Which choice is an example of a hydrogen bond? The bond that forms between:

a hydrogen atom in one water molecule and an oxygen atom in another water molecule.

Which number represents the pH of a solution with the highest concentration of hydrogen ions? (1.0, 9.1, 4.5, 11.5, and 7.0)

1.0

Which atom is the most electronegative?

Oxygen

A woman's doctor tells her to gargle with salt water. She stirs a tablespoon of salt into a cup of warm water, and watches it dissolve. Why does the salt dissolve in water?

The partial positives charges on hydrogen atoms in water molecules are attracted to chlorine ions, and the partial negative charges on oxygen atoms in water molecules are attracted to sodium ions.