Chemical Bonds Questions
Which of these molecules would you least expect to easily dissolve in water?
2-methylpropane is a hydrocarbon with multiple nonpolar C--H bonds. Hydrophobic, polar molecules like water will form two layers with this and will not mix. Nonmiscible.
In water, hydrogen bonds can form between which of the following?
A hydrogen bond is a intermolecular force, occurring between a hydrogen atom of one water molecule and an oxygen of another. One is positive, the other negative. Bonds within and intramolecular bonds.
Which of the following is unlikely to be hydrophilic?
A molecule with primarily nonpolar covalent bonds. They do not carry partial charges, which doesn't allow them to interact with water.
A base is a molecule that will ______ a proton in water
Accept. They remove a proton from a water molecule. If the hydrogen atoms in water are more attracted to the electronegative atom of a base, they can be stripped off as a proton.
You have developed a promising anti-cancer agent, but it has poor solubility in water. Which of the following changes should improve water solubility?
Adding a hydroxyl (-OH) and carboxyl (-COOH) group. Both contain polar oxygen molecules that can form hydrogen bonds with water.
A molecule with a lot of polar covalent bonds is likely to
Be highly soluble. Water has partial positive and negative charges and thus will easily interact with other molecules' partial charges, making it soluble.
Which of the following covalent bonds is relatively nonpolar?
C--H attract electrons fairly easily. Compounds that contain all carbon and hydrogen are nonpolar hydrocarbons and are Nonmiscible in water. Nonpolar bonds share electrons equally.
Organic chemistry is the study of what type of molecules?
Carbon-to-hydrogen bonds.
Which of the following atoms is most likely to participate in an ionic bond?
Chlorine can readily accept a single electron to form an ionic bond. Gaining one electron creates the chloride anion with a -1 charge. When the halogen, Cl, accepts an electron to become a halide ion, then this anion can associate with a metal cation to form a salt.
Identify types of bonds.
Covalent bond (sharing of electrons), ionic bond (transfer of electrons), hydrogen bond
What type of bond is formed when two atoms share electrons?
Covalent.
Which type of bond is the strongest in cells
Covalent. They are resistant to being broken by thermal motion or dissolution in water. Occurs between two nonmetal atoms.
Which type of bond makes it possible for a macromolecule to interact with great specificity with just one out of the many thousands of different molecules present inside a cell?
Different types of weak noncovalent bonds act together to allow a macromolecule to interact with another. These can be disrupted with heat or by changing the pH of the solution.
In cells, electrostatic attractions are stronger than covalent bonds.
False. Covalent bonds do not break when the temperature elevates, but electrostatic interactions will. Electrostatic interactions happen between chemicals that are opposite in charge, therefore, no electron for sharing.
Carbon can form a maximum of how many covalent bonds with other atoms?
Four
Which statement is true of hydrophilic molecules?
Hydrophilic molecules dissolve in water. "Water loving." Hydrophobic are uncharged and do not dissolve.
Which of the following occurs by bringing nonpolar surfaces together to exclude water?
Hydrophobic forces
The type of chemical bond is? (donating of one electron) When sodium loses an outer electron, it becomes positively charged, called?
Ionic bond, cation.
Which type of bond is formed when one atom donates electrons to another atom?
Ionic bonds. Once this electron transfer happens, the ions are attracted to one another, thereby forming the ionic bond.
What distinguishes the chemistry of life from other types of chemistry?
Life is dominated by polymers and takes place almost exclusively in water. Sugars, fatty acids, amino acids, and nucleotides are the four main families of small organic molecules in cells. All produced in the cytoplasm.
Which of the following chemical groups could confer nonpolar/hydrophobic characteristics on the region of a molecule in which it is found?
Methyl group (-COOH). Bonds between H and electronegative atoms like O and N are polar and tend to impart hydrophilic characteristics.
Consider an O--H covalent bond in H2O. In H2O, the atom more strongly attracts electron and acquires a partial negative charge within the molecule itself.
Oxygen is more electronegative than hydrogen and is strongly attractive for electron. Thus, acquires a partial negative charge.
Which bond describes a colavent bond in which electrons are shared unequally?
Polar. The positive charge will be concentrated toward on end of the molecule and the negative toward the other.
What is the best term to describe a chemical held together solely by ionic bonds?
Salts. Formed by the attraction between cationic and anionic components. Ex: NaCl. Molecules are held together by covalent bonds, share of outer electrons.
What did you observe in the animation?
The more bonds, the greater the electron affinity.
Acids release protons when they dissolve in water. How does the proton (H+) released by an acid compare to the proton found in the nucleus of an atom?
There is no difference. A hydrogen atom contains a single proton and a single electron. When this atom gives up its electron, there is a positive hydrogen nucleus--a proton H+. Thus, "protons are protons" and they all behave the same regardless if in an atom or ion.
An oxygen atom, with six electrons in its outer shell, has the capacity to form a max of how many covalent bonds?
Two.
Strong and specific associations between macromolecules or between an enzyme and its substrate are due to
Weak noncovalent associations. Short lived in cells
