2. If a piece of blackboard chalk is heated strongly, the mass of the chalk decreases substantially, and the chalk is converted into a fine powder. What evidence is there for a chemical reaction having taken place when the chalk is heated? 3. If you have had a clogged sink drain at your home, you might have tried using a commercial drain cleaner to dissolve the clog. What evidence is there that such drain cleaners work by chemical reaction?
4. If a bottle of aspirin is left open to air, eventually one of the products is acetic acid (vinegar is a mixture of acetic acid and water). Is there evidence that this change represents a chemical reaction?
5. The question present before a chemical reaction takes place are called the , and the substance present after the reaction takes place are called the .
6. in a ordinary chemical reaction, are neither created nor destroyed.
7. The notation "(g)" after a substance's formula indicates that the substance exists in the state.
8. In a chemical equation for a reaction, the notation "(g)" after a substance's formula that the substance is dissolved in .
9. If calcium carbonate is heated strongly, carbon dioxide gas is driven off, leaving a residue of calcium oxide. write the unbalanced chemical equation for this process
10. Liquefied propane gas is often used for cooking in suburban areas away from natural gas lines. propane (C2H8) burns in oxygen gas, producing carbon dioxide gas, water vapor, and heat. write the unbalanced chemical equation for this process.
11. if a sample of pure hydrogen gas is ignited very carefully, the oxygen gas of the air to form water vapor. write the unbalanced chemical equation for this reaction