Download Chemistry Test – Chapters 12 and 13

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Chemistry Test – Chapters 12 and 13
All questions are 4 points each. Use additional sheets of paper to answer the questions.
Write legibly. Show all you work in answering the questions requiring mathematical
calculations.
1. How many atoms are contained in a 46.0 g of sodium?
2. How many hydrogen sulfide molecules (H2S) are in a 68.0 g of the substance?
3. An amino acid that cannot be made (synthesized) by the body and must be
obtained in the diet is lysine. Determine the molar mass of lysine, which has the
following formula:
H2N — (CH2)3 — CHCOOH

NH2
4. Calculate the number of moles in 84.2 g of potassium sulfate.
5.
Magnesium reacts with hydrochloric acid to produce magnesium chloride and
hydrogen gas. If 20.0 g of magnesium react with excess hydrochloric acid, how
many grams of magnesium chloride are produced?
6. Calculate the number of moles in 6500ml of sulfur dioxide gas at STP?
7. Hydrogen gas reacts with copper II oxide to form copper metal and water vapor.
What mass of copper is produced if 255L of hydrogen at STP are used up in this
reaction?
8. If 14.7g of sodium peroxide (Na2O2) reacts with water to produce sodium
hydroxide and oxygen, how many L of oxygen are produced at 220C and
101.2kPa?
9. How many moles are there in 750ml of oxygen at 270C and 99.0kPa?
10. Calculate the volume 150.0g of chlorine will occupy at -12.50C and 98.5kPa?
11. Urea, CO(NH2)2, and ammonia, are two compounds used as a source of nitrogen
in fertilizers. Calculate the mass percent of nitrogen in each?
12. Determine the empirical formula for an iron ore that is 72.4% iron and 27.6%
oxygen.
13. The molar mass of a compound is 92 grams. Analysis of the compound shows
that there are .608 grams of nitrogen and 1.388 grams of oxygen. What is the
molecular formula of this compound?
14. Sodium hydrogen carbonate (NaHCO3) is heated to produce carbon dioxide gas,
sodium carbonate, and water. How many grams of NaHCO3 must be heated to
produce 2.50L of carbon dioxide gas at 22.50C and 97.5kPa?
15. Explain how water can be a solvent to many ionic compounds and can also be a
solvent to many covalent compounds.
16. Explain hydrogen bonding.
17. Explain osmosis, and how it works.
18. Explain the differences between unsaturated, saturated, and supersaturated.
19. A laboratory requires 0.100M lead II nitrate. How many grams of lead II nitrate
are required to make 175ml of the solution?
20. How many grams of sodium carbonate heptahydrate are required to make 1000ml
of a 1.21M solution?
21. Calculate the molarity of a 1.50L solution containing 102g of potassium
hydroxide.
22. Photosynthesis is a complex process composed of many steps. The initial
reactants are carbon dioxide and water, and the final products are glucose and
oxygen. If a plant needs to make 30g of glucose through the process of
photosynthesis, how many grams of water are required?
23. A flask has a volume of 225ml. A gas with a mass of 2.75g is introduced into the
flask at a temperature of 302.0k and a pressure of 9.76 x 104 Pa. Calculate the
molar mass of the gas.
24. Copper metal (Cu) is reacted with silver nitrate to produce copper II nitrate and
silver metal. If 5.00g of copper metal reacts with a solution containing 20.0g of
AgNO3, how many grams of silver metal will be produced from the reaction?
25. Explain the difference between an endothermic reaction and an exothermic
reaction.