Relative formula mass

What is relative formula mass?

It is the sum of the relative atomic masses of all atoms in a formula.

How do you calculate the relative formula mass of H₂O?

Add the relative atomic mass of hydrogen (1) × 2 and oxygen (16), so 2 + 16 = 18.

What is the relative formula mass of CO₂?

Carbon (12) + oxygen (16) × 2 = 12 + 32 = 44.

Why do we use relative atomic masses in calculating formula mass?

Because they are weighted averages based on isotopic abundance.

What is the formula mass of NaCl?

Sodium (23) + chlorine (35.5) = 58.5.

What is the relative formula mass of a compound with the formula C₆H₁₂O₆?

Carbon (12) × 6 + hydrogen (1) × 12 + oxygen (16) × 6 = 72 + 12 + 96 = 180.

How is relative formula mass different from molecular mass?

Molecular mass refers to the mass of a molecule, which can be molecular or empirical.

What is the relative formula mass of H₂SO₄?

Hydrogen (1) × 2 + sulfur (32) + oxygen (16) × 4 = 98.

How does the relative formula mass relate to the actual mass of a sample?

It allows us to calculate the mass of a given number of molecules or moles.

How would you calculate the relative formula mass of a compound with multiple elements?

Add the atomic masses of each element in the correct proportions as shown in the formula.

What is the relative formula mass of NH₃?

Nitrogen (14) + hydrogen (1) × 3 = 17.

What is the formula mass of Al₂O₃?

Aluminum (27) × 2 + oxygen (16) × 3 = 54 + 48 = 102.

How does the relative formula mass affect stoichiometry calculations?

It helps in determining the molar relationships in balanced chemical equations.

If you have 1 mole of a compound with a relative formula mass of 58, how many grams do you have?

58 grams.

How do you find the relative formula mass of an unknown substance?

Use experimental methods like mass spectrometry or by calculating from known formula.