| Question | Answer |
| 1. Why should a chemical equation be balanced? | See answer key
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2. Why are decomposition reactions called the opposite of combination reactions? | See answer key
| 3. What do you think the subscripts in the chemical formulas represent? | See answer key
| 4. How many of a particular atom are present in a compound when there is no subscript written? | See answer key
| 5. What is added to the formula to indicate that more than one copy of a group of atoms is present in a compound? | See answer key
| 6. How is the number of atom groups indicated in the formula when parentheses are present? | See answer key
| 7. Compare the charges on the polyatomic ions. Are the majority of the charges positive or negative? | See answer key
| 8. Which polyatomic ion is positively charged? (Write the name and the formula) | See answer key
| 9. Where are the negatively charged polyatomic ions located in compound formulas – at the beginning or the end of the compound? | See answer key
| 10. Where are the positively charged polyatomic ions located in the compound formulas – at the beginning or the end of the compound? | See answer key
| 11. Do the names of the metal elements change when they are written in compound names? If yes, how do they change? | See answer key
| 12. Do the names of the nonmetal elements change when they are written in compound names? If yes, how do they change? | See answer key
| 13. Do the names of the polyatomic ions change when they are written in compound names? If yes, how do they change? | See answer key
| 14. What do you think the Roman Numerals in compound names represent? | See answer key
| 15. A substance that enters into a chemical reaction is called a: | see answer key
| 16. The word equation “magnesium reacts with chlorine to produce magnesium chloride” would be represented by which formula equation? | answer key
| 17. In a chemical equation, the number of molecules of a given substance is indicated by a: | answer key
| 18. Which of the following symbols means a substance is in a water solution – (s), (aq), (w), (l)? | answer key
| 19. What is the general form for a single-replacement reaction (i.e. A + B ---> C) | answer key
| 20. What is the general form for a double-replacement reaction (i.e. A + B ---> C) | answer key
| 21. A solid produced by a chemical reaction in solution that separates from the solution is called? | answer key
| 22. The reaction 2Mg(s) + O2(g) ---> 2MgO(s) is what type of reaction: synthesis, decomposition, single replacement, double replacement, neutralization? | answer key
| 23. The reaction Mg(s) + HCl(aq) ---> MgCl2(aq) + H2(g) is what type of reaction: synthesis, decomposition, single replacement, double replacement, neutralization? | answer key
| 24. The reaction CaCO3(s) ---> CaO(s) + CO2(g) is what type of reaction: synthesis, decomposition, single replacement, double replacement, neutralization? | answer key
| 25. The reaction Pb(NO3)2(aq) + 2KI(aq) ---> PbI2(s) + 2KNO3(aq) is what type of reaction: synthesis, decomposition, single replacement, double replacement, neutralization? | answer key
| 26. What type of ion gains electrons and has a negative charge? | answer key
| 27. What type of bond involves a sharing of valence electrons? | answer key
| 28. What is the correct chemical formula and name when a calcium ion transfers electrons with a nitrate polyatomic ion to form a compound? | answer key
| 29. Molar mass is measured using units of _________. | answer key
| 30. Susan collects an actual mass of 5.30 g of product, compared to 6.04 g that should have been collected. Based on her calculations, what is the percent error? | answer key
| 31. What percent of carbon monoxide is oxygen? | answer key
| 32. Some underwater welding is done via the thermite reaction, in which rust (Fe2O3) reacts with aluminum to produce iron and aluminum oxide (Al2O3). In one such reaction, 258 g of aluminum and excess rust produced 464 g of iron. What was the percent yield of this reaction? | answer key
| 33. In a reaction where potassium chlorate decomposes into potassium chloride and oxygen gas, how many grams of potassium chloride is produced if 2.50 g of potassium chlorate is decomposed? | answer key
| 34. In a reaction where potassium chlorate decomposes into potassium chloride and oxygen gas, how many liters of O2 is produced if 5.00 moles of potassium chlorate is used? | answer key
| 35. Given the balanced equation: 2N2H4(l) + N2O4(l) 3N2(g) + 4H2O(g), how many moles of dinitrogen tetrahydride are required to produce 57 moles of nitrogen? How many moles of dinitrogen tetroxide are required to produce 57 moles of nitrogen? | answer key
| 36. Camels store the fat tristearin (C57H110O6) in the hump. As well as being a source of energy, the fat is a source of water, because when it is used the (unbalanced) reaction: C57H110O6 (s) + O2(g) ---> CO2(g) + H2O(l) takes place. At STP, what volume of oxygen is required to consume 0.64 moles of tristearin? If 22.4 L of oxygen is consumed at STP, how many moles of water are produced? Find the mass of tristearin required to produce 55.56 moles of water? | answer key
| 37. How many moles are there in 458 grams of Na2SO4? | answer key
| 38. How many grams are there in 7.40 moles of silver nitrate? | answer key
| 39. How many molecules are there in 2.30 g of NH3 (ammonia)? | answer key
| 40. Chlorobenzene (C6H5Cl) is used in the production of various chemicals such as insecticides and dyes. One way that chlorobenzene is prepared is by reacting benzene (C6H6) with chlorine gas according to the following BALANCED equation: C6H6(l) + Cl2(g) ---> C6H5Cl(s) + HCl(g). What is the theoretical yield if 45.6 g of benzene react? If the actual yield is 63.7 g of chlorobenzene, calculate the percent yield. | answer key |
