Question

To calculate the amounts of reactants, we must use:




the reactivity of each elements


the force of attraction of each atoms


chemical equations


molecular activity for each atom

Answer 1

Correct answer: chemical equations.

Explanation and how to use them:
- Balanced chemical equations give the mole ratios between reactants and products, which you use to calculate amounts.
- Steps to calculate amounts:
1. Write and balance the chemical equation.
2. Convert given masses/volumes/particles to moles (use molar mass, ideal gas law, or Avogadro’s number as appropriate).
3. Use the stoichiometric mole ratios from the balanced equation to find moles of the desired substance.
4. Convert moles back to mass or volume if required.
5. Check for a limiting reagent and compute theoretical yield; compare to actual yield to get percent yield if needed.

Notes on the other choices:
- Reactivity can tell whether a reaction will occur, but not the quantitative amounts required.
- “Force of attraction of each atom” and “molecular activity for each atom” are not used in stoichiometric calculations.