Explanation

A Lewis base is a substance that donates a pair of electrons to form a coordinate covalent bond.

This means that a Lewis base is an electron pair donor.

Explanation

CN (cyanide ion) is a Lewis base.

Because it donates an electron pair to form a coordinate covalent bond.

Explanation

According to the Bronsted-Lowry theory, NH3 acts as a base because it can accept a proton (H^+).

According to the Lewis theory, NH3 is a base because it can donate a pair of electrons.

Explanation

According to the Arrhenius definition, an acid is a substance that increases the H+ ion concentration in aqueous solution.

HCl, HNO3, and H2SO4 all dissociate in water to produce H+ ions, making them Arrhenius acids.

CO2 does not dissociate in water to produce H+ ions.

Explanation

Preservatives are used to prevent the growth of microorganisms, such as bacteria, yeast, and mold, in food.

They help to extend the shelf life of food products and prevent spoilage.

Preservatives can be found in meats, dairy products, baked goods, and beverages.

Explanation

Acids are known to cause corrosive effects on skin, including burns, ulcers, and damage to skin tissue.

Examples of corrosive acids include sulfuric acid (H2SO4), hydrochloric acid (HCl), and nitric acid (HNO3).

Explanation

The value of Kc (equilibrium constant) increases when the concentration of the product increases.

This is because Kc is a measure of the ratio of products to reactants at equilibrium.

A higher product concentration means a greater tendency for the reaction to proceed in the forward direction.

Explanation

Qc (reaction quotient) is defined as the ratio of the molar concentrations of products to reactants, each raised to the power of their respective stoichiometric coefficients (coefficients in the balanced chemical equation).

Explanation

When the reaction quotient (Qc) is equal to the equilibrium constant (Kc), the system is at equilibrium and is stable.

Qc = Kc indicates that the rates of forward and reverse reactions are equal, and the concentrations of reactants and products remain constant.

Explanation