Which type of stoichiometric calculation does not require the use of the molar mass?

• A. Mass-to-mole calculation
• B. Mole-to-mass calculation
• C. Mole-to-mole calculation
• D. Mass-to-mass calculation

Answer: (C)

Verified step by step guidance

1. Understand that stoichiometric calculations often involve converting between mass and moles of substances using the molar mass as a conversion factor.
2. Recognize that a mass-to-mole calculation requires converting a given mass of a substance to moles, which involves dividing by the molar mass: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
3. Know that a mole-to-mass calculation requires converting moles to mass, which involves multiplying by the molar mass: \(\text{mass} = \text{moles} \times \text{molar mass}\).
4. Identify that a mole-to-mole calculation involves using the mole ratio from the balanced chemical equation to convert moles of one substance directly to moles of another, without needing molar mass.
5. Conclude that since mole-to-mole calculations use only mole ratios from the balanced equation, they do not require the molar mass.