Moles, Percent Comp, Formulas Review

Front

What is the molar mass of H₂O?

Back

18 g/mol (calculated as 2*1 + 16 = 18)

Front

Define a mole in chemistry.

Back

A mole is a large number (6.022 x 10²³) used to count particles, such as atoms or molecules.

Front

What information can be obtained from a balanced chemical equation?

Back

The mole ratio of any two substances in the reaction.

Front

Calculate the percent by mass of chlorine in NaCl (Na = 23 g/mol, Cl = 35.5 g/mol).

Back

61% (calculated as (35.5 / (23 + 35.5)) * 100)

Front

What percentage of the total atomic mass of carbon monoxide (CO) is composed of carbon? (C = 12 g/mol, O = 16 g/mol)

Back

43% (calculated as (12 / (12 + 16)) * 100)

Front

What is the formula to calculate percent composition by mass?

Back

Percent composition = (mass of element / total mass of compound) * 100

Front

How do you find the empirical formula from percent composition?

Back

Convert percent to grams, divide by molar mass to find moles, and simplify the ratio.

Front

What is the difference between empirical and molecular formulas?

Back

Empirical formula shows the simplest ratio of elements, while molecular formula shows the actual number of atoms.

Front

What is the significance of the mole ratio in a chemical reaction?

Back

It allows for the calculation of reactants and products in a reaction based on their coefficients.

Front

How do you calculate the molar mass of a compound?

Back

Add the molar masses of all the elements in the compound based on their quantities.