NAT SCI 1 SEMI-FINAL EXAM

1. This represents with symbols and formulas, the identities and relative amounts of the reactants and products in a chemical reaction.

• chemical formula

• chemical reaction

• chemical equation

• chemical inventory

2. A solid produced by a chemical reaction.

• slush

• gel

• aqueous solution

• precipitate

3. Whole number that appears in front of a formula in a chemical equation. (Example: 6 in the following: 6 NaOH)

• coefficient

• superscript

• catalyst

• superscript

4. This symbol indicates_____________

• reacts to yield

• beware of sharp edges

• a reversible reaction

• reactivity increases with items to

5. This symbol indicates_____________

• reacts to yield

• beware of sharp edges

• a reversible reaction

• reactivity increases with items to

6. Fill in the blanks with coefficients to balance this equation:PCl5+___ H2O→____ HCl+H3PO4

• 4, 5

• 1, 6

• 3, 8

• 2,2

7. Balance this equation ___Zn +___HCl --> ____ZnCl2 + _____H2

• 1,1,2,1

• 1,1,1,2

• 1,2,1,1

• 2,1,1,1

8. Balance this equation. ___Mg + ___Cl2 --> ___MgCl2

• 1, 2,1

• already balanced

• 2,1,1

• 1,1,2

9. Balance this equation ___N2 + ___H2 --> ___NH3

• 1,2,3

• 1,3,2

• 1,1,2

• 2,1,1

10. The blue numbers in the image below represent ________

• Charges

• coefficients

• subscripts

• none of the answers are correct