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CHEM 120 Week 5 Exam 2

1. A solution is prepared by dissolving 50 g of KCl (74.6 g/mol) to a volume of 1 L. What is the molarity of this solution?
2. You prepare a solution by dissolving 20 g of NaCl to a volume of 350 mL in What is the mass/volume % concentration of this solution?
3. When the following reaction goes in the forward direction, what is the base?
4. You are preparing a buffered soluti So far, your solution contains H2PO4-  ions, what would you add to this solution to prepare your buffer system?
5. Select all examples where the Law of Conservation of Mass in not being followed. Select all that
6. Balance the following chemical equation: FeBr₃ + H₂O → HBr + Fe₂O₃ (4 points).
7. What would be the products of the neutralization equation Select all that apply!
8. Calculate the Volume, in L, of 9.6 mole sample of oxygen gas at a pressure of 6.5 ATM at 16 °C. Show all work (5 points)
9. If you have 0.4 moles of C3H8 that you combust (balanced chemical reaction is: C3H8   + 3 O2  → 3 CO2  + 4 H2O), how many moles of CO2  will you generate?
10. I have 670 grams of O2. How many moles of O2 do I have?
11. You are looking at the results of a series of tests to determine if a series of solutions, A-E, would be considered Select ALL that you think are acidic based on the results below.
12. You have added HCl to What would you expect to occur?
13. If you increased the temperature of a sample of a gas, what would you expect would happen to the volume of the gas at a fixed pressure?
14. How many iron atoms are in Iron(III) chloride
15. In the chemical reaction 2 K(s) + 2 H₂O(l) →2 KOH(aq) + H₂(g) chose the statement that is
16. When 2.5 grams of sodium nitrate is dissolved in 60 ml of water in a beaker, the solute is the:
17. Consider vinegar and oil shaken together to form a mixture of with small droplets of oil dispersed in the vinegar. The best term for this would be:
18. A common chemical used in water treatment is Al₂(SO₄)₃. What is the molecular mass of this compound?
19. In the equation: Al(s) + HCl(g) → AlCl₃(s) + H₂(g), select all reagents that would be considered Select all that apply.
20. Select all solutions that would be considered
21. You have 2 L of a 10% NaCl How many L of a 0.9% solution can you produce by diluting this solution? Show all of your work. (5 points total).
22. If a sample of gas with a volume of 20 ml at a pressure of 6 atm is moved to an area with a pressure of 2 ATM, what is the new volume of the gas?
23. For the following, consider a balloon filled with Assuming ideal gas behavior, predict the effect: (4 points)
24. Balance the chemical equation below (4 points) SiF₄ + H₂O → SiO₂ + HF
25. 0 grams of NaHCO₃ decomposes following the balanced reaction below. How many grams of H₂O will you form? Show all work.(6 points). 2 NaHCO₃ → H₂O + CO₂ + Na₂CO₃
26. You dissolve a sample of MgF₂ in The molarity of this solution is 1.4 M. What is the osmolarity of this solution? Show all work and units. Show all work. (5 points total)
27. If you dissolved 18 grams of NaBr (molecular mass 102.89 g/mol) in water to prepare 640 ml of solution, what is the Molarity of this solution? Show all work. (5 points)
28. Predict the products of this neutralization reaction. (4 points) HBr + NaOH ⟶
    

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CHEM 120 Week 5 Exam 2

PART 1: Multiple Choice questions: Q 1-24. (2 point each)

1. Chemical reactions (equations) show the following
2. The following is true for a mole
3. In balancing chemical equations, the coefficients are used to
4. 2H2 + O2 2H2O means that
5. 2H2 + O2 2H2O. In this equation, correct method to calculate molecular mass of water is
6. One mole of O2 gas contains number of molecules.
7. Concentration of a solution is _____
8. The following is a product of reaction of a nonmetal oxide with water to make acid.
9. If CaO reacts with water, the following product will be made.
10. The following will be made when KOH reacts with HCl.
11. “The neutralization reaction is a quantitative reaction, where amount of acid needed to neutralize the base can be accurately calculated.” This statement is _____
12. The pH scale represents the _____
13. Buffer solution is a solution _____
14. Oxidation is defined as . It occurs on a/an   _____.
15. Reduction is defined as _____ . It occurs on a/an _.
16. Oxidizing agents cause _____. During that process they themselves are __.
17. Reducing agents cause . During that process they themselves are           __
18. Silver tarnish is an example of _____   
19. Oxygen is a _____.
20. Photosynthesis combines CO2 and H2O into glucose via a series of __ reactions.
21. ellular Respiration generates CO2 and H2O from glucose via a series of ____ reactions.
22. The following is true for Boyle’s law.
23. The following is true for Charles’s law.
24. At STP, what would be the molar mass of a gas with density of 2.1g/L?

PART 2: Write units and show ALL work.

25. Calculate the molarity of a 250 ml solution containing 420g Aluminum hydroxide (2 points).
26. 0.5 M stock solution of NaCl was diluted to 50 mM solution in 350 ml volume. Calculate the volume needed to make this dilution. (2 points)
27. (a) Complete and balance the reactions given below. (b) Answer the given question (5 points). b. Calculate the amount in gram of acid needed to produce 50 g of Salt.
28. Calculate the pressure, in atmospheres, of 9.81 mol CO(g) in a 7.5 L tank at 35 degrees C. (3 points)