What is the oxidation number of carbon in NaHCO3?

Correct Answer: Nucleotides

Explanation:

Nucleic acids are polymers of individual nucleotide monomers.

Each nucleotide is composed of three parts:

a 5-carbon sugar,

a phosphate group, and

a nitrogenous base.

Correct Answer: high pressure and low temperature

Explanation:

Henry's Law tells that the solubility of a gas is directly proportional to the partial pressure of the gas above the solvent. Hence under high pressure, more gas is dissolved.

Also that Henry's Law involves a constant which is temperature-dependent. Under high temperatures, less gas is dissolved whereas under low temperatures, more gas is dissolved.

 

For Example ::  

You can think of a can of soda. The contents are under pressure and if you shake the can before opening, the soda fizzes out all over as you open it. So the higher the pressure, the more gas or more CO2 can be dissolved in the drink.

Eliminate choices 1 and 2. Now focus on the temperature. Soda goes flat (loses carbonation or gas) as it warms up. Soda is usually served cold because more of the carbonation or CO2 stays in the drink when the soda is cold.

 

Hence, in high pressure and low temperature conditions gases are most soluble in water.

Correct Answer: Both A & B

Explanation:

Covalent bonds hold atoms together because the attraction between the positively charged nuclei and the negatively charged shared electrons is greater than the repulsions between the nuclei themselves.

Correct Answer: All of the above

Explanation:

A metalloid is any chemical element which has properties in between those of metals and nonmetals, or that has a mixture of them.

The six commonly recognised metalloids are

boron,

silicon,

germanium,

arsenic,

antimony, and

tellurium.

Correct Answer: All of the above

Explanation:

The halogens make up group 17 in the periodic table.

They are five elements:

Chlorine (Cl)

Fluorine (F)

Bromine (B)

Iodine (I)

Astatine (At).

But astatine is not purely halogen as it is radioactive.

Correct Answer: bonds

Explanation:

chemical energy is contained in the chemical bonds between the reactants in the chemical compounds.

Correct Answer: Ionic bonding is a type of chemical bond in which valence electrons are lost from one atom and gained by another This bond generates two oppositely charged ions In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion Example :: One example of an ionic bond is the formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom In this reaction, the sodium atom loses its single valence electron to the fluorine atom, which has just enough space to accept it The ions produced are oppositely charged and are attracted to one another due to electrostatic forces

Correct Answer: Weak bonds are transient and easily reversible.

Explanation:

In chemistry, Weak bonds are those forces of attraction that, do not take a large amount of energy to break.

 

For example, hydrogen bonds are broken by energies in the order of 4 - 5 kcal/mol.

Ionic bonds, hydrogen bonds and van der Waals interactions are considered weak bonds.

 

Weak bonds are transient and easily reversible.

Correct Answer: All of the above

Explanation:

Yes, all the given statements are NOT true about electrons and atomic orbitals.

 

True statements are ::

 

An orbital can contain a maximum of two electrons.

An atom?s lowest energy level has only one orbital.

An electron has different amount of energies in all orbitals.

Correct Answer: Au3+ + 3e? ---> Au

Explanation:

A half reaction is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction.