Chemistry Second Semester 24 Review

Front

How many atoms are in 1 mole of a substance?

Back

1 mole of any substance contains approximately 6.022 x 10^23 atoms (Avogadro's number).

Front

What is the molar mass of a compound?

Back

The molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all atoms in the compound.

Front

What is a limiting reactant?

Back

The limiting reactant is the substance that is completely consumed in a chemical reaction, limiting the amount of product formed.

Front

How do you calculate the empirical formula from percent composition?

Back

Convert the percentage of each element to grams, then to moles, and divide by the smallest number of moles to find the simplest whole number ratio.

Front

What is the balanced equation for the reaction of magnesium with hydrochloric acid?

Back

Mg + 2 HCl → MgCl2 + H2.

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations ensures that the law of conservation of mass is obeyed, meaning the number of atoms of each element is the same on both sides of the equation.

Front

What is the molecular formula?

Back

The molecular formula shows the actual number of atoms of each element in a molecule, as opposed to the empirical formula which shows the simplest ratio.

Front

What is the role of oxygen in combustion reactions?

Back

Oxygen acts as an oxidizing agent, reacting with a fuel to produce heat and light, typically resulting in carbon dioxide and water.

Front

What is the difference between an ionic bond and a covalent bond?

Back

An ionic bond is formed through the transfer of electrons from one atom to another, while a covalent bond is formed by the sharing of electrons between atoms.

Front

What is the pH scale?

Back

The pH scale measures the acidity or basicity of a solution, ranging from 0 (very acidic) to 14 (very basic), with 7 being neutral.