General Chemistry
Name the Apparatus! (Image #9)
Image #9 Answer!
Which of these compounds are polar?
H-Br
C=O=C
F-F
H-Br
What is the heat capacity of water?
4.18
Which is more electronegative? Oxygen or Chlorine?
Oxygen
The pOH level of Lake Lake to be 11.3. Find me the pH level of Lake Lake.
14-11.3 =3.7
pH= 3.7
What is the subshell notation of Copper (Cu)?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰
Name this Organic Chemical (Image #6)
3-Bromo-4-Flurohexane
What are the three things needed to be measured to calculate the enthalpy of combustion?
Mass of Water (m), change in temperature (ΔT), mass of fuel being combusted (m) (for mols)
Below are two reactions. One will generate volts of electricity while the other will do nothing. Which one generates volts?
Reaction 1: Li + Fe+1 --> Li+1 + Fe
Reaction 2: Li+1 + Fe --> Li + Fe+1
Reaction 1: Li + Fe+1 --> Li+1 + Fe
The Lithium can give an electron to iron, creating a circuit and the flow of electricity to generate volts.
Write me two equations to show that Water is amphiprotic.
H2O --> OH- + H+ (proton donor)
H2O + H+ --> H3O+ (proton acceptor)
Draw me the Lewis Structure of CO2
Image #12
Which compound would have the highest boiling point? Hexan-1-ol, Hexan-1-al, Hexanoic Acid. Explain why this is?
Hexanoic acid has the highest boiling point because it has more sites for hydrogen-bonding to occur, causing a stronger secondary interaction compared to the dipole-dipole interactions of the Hexan-1-al.
I decide to carry out an investigation to determine the molar enthalpy of the combustion of ethanol. I use a standard calorimeter apparatus to heat up water in an open spirit burner flame. I get the experimental molar enthalpy of -270KJ/mol. The true value is -1367KJ/mol.
Name one source of error to account for this value and suggest a solution to minimise this effect.
Source of error:
1. No insulation (heat loss to the environment)
2. Could be an incomplete combustion that results in less energy compared to a complete combustion.
Minimise effect:
1. Insulate the apparatus.
2. Ensure there is enough Oxygen gas to allow for complete combustion to occur.
I react a calcium sulphate solution with iron, lithium, and bismuth. The solution reacted slow with iron, fast with bismuth, and there was no reaction between the calcium sulphate and lithium.
Rank these 4 elements from highest to lowest in the activity series.
Lithium
Calcium
Iron
Bismuth
Which of these compound are basic oxides?
SO2
MgO
Na2O
MgO + H2O --> Mg(OH)2 (makes a base so it's a basic oxide)
Na2O + H2O --> 2NaOH (makes a base so it's a basic oxide)
Draw and label the metallic bonding structure.
Image #11
(Words have to be included: Electrostatic force of attraction, delocalised electrons, metal ion)
Draw and name me the polymer of ethene.
Hint: Image #10
Polythene/Polyethylene
Image #11
Draw and label a diagram of a simple calorimeter experiment. Specific volumes are not required.
Image #8
What is the oxidation half equation of:
C3H7OH + Cr2O7-2 --> C3H6O + Cr+3
C3H7OH --> C3H6O + 2H+ + 2e-
Explain to me using a chemical equation why Sealife shells and exoskeletons (CaCO3) are being dissolved in the increased proton (H+) concentration.
2H+ + CaCO3 --> H2O + CO2 + Ca+2
I react methane with oxygen gas to create carbon dioxide and water. Balance the equation. I use 4.8 mols of methane. How many water mols are created?
This is the equation:
CH4 + O2 --> CO2 + H2O
CH4 + 2O2 --> CO2 + 2H2O
Ration: 1:2
4.8CH4 X 2 = MolsH2O
H2O mols = 9.6 mols
I decide to add Heptane-1,2,7-triol to a Potassium dichromate (K2CrO7) solution. Draw me the new molecule.
Hint: Image #7
The end chain linked alcohols should become aldehydes and the 2-carbon linked alcohol should become a ketone.
Sucrose, more commonly known as sugar is a complex hydrocarbon. It's also a very tasty ingredient that makes the gingerbread you're eating taste sweet. I want to burn it! I burn 0.0004 mols of sucrose to heat up a volume of water by 75o Celsius. I get the a molar enthalpy of -400KJ/mol. Find me the mass (m) of water.
510.367g
Write me the the overall simplified balanced equation in alkaline conditions for:
Cu + MnO4-2 --> CuO + MnO2
Oxidation: Cu --> CuO
2OH- + H2O + Cu --> CuO + 2H+ + 2OH- + 2e-
Reduction: MnO4 --> MnO2
2e- + 4OH- + 4H+ + MnO4-2 --> MnO2 + 2H2O + 4OH-
Overall: 2e- + 6OH- + 4H+ + H2O + MnO4-2 + Cu --> MnO2 + CuO + 2H2O + 6OH- + 2H+ + 2e-
Simplified: 2H+ + MnO4-2 + Cu --> MnO2 + CuO + H2O
I combine Sodium Bicarbonate with Hydrochloric acid. Write the full equation.
NaHCO3 + HCl --> H2O + CO2 + NaCl