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Chemistry Study Questions

1. What scientific principle or law is used in the process of balancing chemical equations?
2. In balancing equations, why should you not change subscripts in chemical formulas?
3. Define the terms limiting reactant and excess reactant.
4. Why are the amounts of products formed in a reaction determined only by the amount of the limiting reactant?
5. Why should you base your choice of what compound is the limiting reactant on its number of initial moles, not on its initial mass in grams?
6. Explain why the general trend exists for elements getting smaller as you move across a period on the periodic table.
7. Explain the importance of the VSEPR Theory.

Solution Preview

1. Conservation of mass is used in a reaction, if you start with a total of 'x' grams of reactant, the sum of the masses of all products should equal 'x' grams.

2. Changing subscripts of a formula leads to a completely different compound. Even though the number of atoms may remain the same, the compounds will be different. So if 2 moles of CO2 form, you should say 2CO2 rather than C2O4.

3. The limiting reactant is the reactant whose mass (and hence moles) decides the number of moles (and hence mass) of product that can form. It is taken in the least ...

Solution Summary

The expert determines the scientific principles or law used in the process of balancing chemical equations. The terms limiting reactant and excess reactants are determined.