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Which of the following types of batteries can be recharged?
a) alkaline dry cells
b) zinc chloride
c) nickel-cadmium (Ni-Cad)
d) mercury button battery
8. Hydrogen fuel cells:
a) are recharged by plugging them into an electrical outlet.
b) are recharged by filling the cell up with fuel, similar to filling up a gas tank.
c) cannot be recharged.
d) are recharged by using electricity to reverse the chemical reactions that occurred in the cell.
9. The following substance(s) must be present for the corrosion of iron to occur.
a) oxygen and carbon dioxide
b) water and carbon dioxide
c) oxygen and water
d) oxygen 1
0. In the redox reaction of the corrosion of iron which substance is reduced?
a) iron
c) iron(III) oxide
d) water
The cathode is:
a) the negative electrode where reduction takes place.
b) the positive electrode where reduction takes place.
c) the negative electrode where oxidation takes place.
d) the positive electrode where oxidation takes place.
5. In a Daniell cell with a zinc anode the positive charge that builds up in the zinc half- cell compartment is neutralized by:
a) positive ions migrating towards the anode. negative ions migrating towards the cathode.
c) negative ions migrating towards the anode.
d) positive zinc ions, Zn2*, being reduced to produce zinc atoms.
6. During electroplating the metal object to be plated is usually:
a) made the anode in the electrochemical cell.
b) the electrolyte is the electrochemical cell.
c) made the cathode in the electrochemical cell.
d) oxidized.
Explain why H+ and OH- have exceptionally high ionic mobility in Aqueous media. Show schematically.
What are the Names of alkenes groups
Equation to who the reaction of hex-1-ene to hexane with bromine water
Calculate Eºcell for the reactions below to be determine which are spontaneous as written:
a. Co(s) + H+(aq) → Co+2(aq) + H2(g)
b. Mn+2(aq) + Co+3(aq) → MnO2(s) + Co+2(aq) [acidic]
c. Ag(s) + Cu+2(aq) → Ag+(aq) + Cu(s)
9. By mass, a compound contains 28.9% potassium, 23.7% sulfur and the remainder is oxygen. What is the empirical formula of this compound?
10. The percent compositions are given for 2 antibiotics below. Find the empirical formula for each one:
a. 40.87% carbon, 3.72% hydrogen, 8.67% nitrogen, 24.77% oxygen and 21.98% chlorine.
b. 41.86% carbon, 4.65% hydrogen, 16.28% nitrogen, 18.60% oxygen and 18.60% sulfur.
11. Caffeine consists of 49.5% carbon, 5.15% hydrogen and 28.9% nitrogen and the rest is oxygen.
a. What is the empirical formula?
b. Given the molar mass of caffeine is 195g/mol, what is the molecular formula?
12. An ester is a compound with a pleasant odour. One of the esters was analyzed and the data is found below:
How many moles of sodium sulphite are in the 2.67g?
2. How many molecules of potassium acetate are in 4.55mol?
3. What is the mass of 1.76 x 1024 molecules of calcium phosphide?
4. a. How many molecules of aluminum hydroxide are in 2.45 mol?
b. How many atoms of oxygen are in 2.45mol of aluminum hydroxide?
5. What is the %mass of hydrogen in ammonium sulphate?
6. What is the % composition of dinitrogen tetrachloride?
7. What is the empirical formula of a compound made from 60% magnesium and 40% oxygen?
8. What is the empirical formula of a molecule whose percent composition is 21.6% sodium, 33.3% chlorine, and 45.1% oxygen?
Describe your method for interpreting or “reading” spectroscopic data. Explain what information each of the standard spectroscopic / analytical methods provides. Write no more than 3 or 4 sentences. Make sure your writing is clear enough that I can read it
identify the reagents represented by the letters a through d in the following scheme:
