Chem mod 7

IQ4

100

This intermolecular force is responsible for alcohols having much higher boiling points than alkanes of similar molecular mass.

hydrogen bonding

200

When ethanol is heated with concentrated sulfuric acid at 170°C, this class of organic compounds is produced

alkenes

300

This is the product formed when a primary alcohol undergoes complete oxidation under reflux conditions.

carboxylic acid

400

In this process, yeast converts glucose into ethanol and carbon dioxide under anaerobic conditions

fermentation

500

The hydroxyl (-OH) group in alcohols can form hydrogen bonds, while the carbon chain contributes these intermolecular forces that increase with chain length.

London dispersion forces

random chem mod 7

100

OH bond and carbon chain is what?

alcohol

200

conditions needed for bromination of alkane

uv light or heat

300

what do you get when esterification with butan-1-ol and a twice oxidised dodecan-1-ol

butyl dodecanoate

400

what are the top 3 highest priority functional groups in order

carboxylic acid, ester, amide

500

what indicator can be used in titration (name one)

brogothymol blue

luck column

100

200 free points

lets go

200

-200 points

rip

300

free 300 points

nice

400

no points change

lol

500

lose 500

that's unfortunate

Qiming

100

If things are going swimmingly for you in the UK, you might exclaim, "Bob's your" this.

uncle

200

This Australian prime minister disappeared while swimming and was never found.

Harold Holt

300

This prime number is the sum of the first seven primes minus the seventh prime.

41

400

Bananas are naturally radioactive because they contain this element.

potassium

500

This acorn-obsessed critter from the Ice Age films caused a "continental crack-up."

Scrat

easy column

100

who was in the winning titration team?

Yukai, Finn, AJ

200

What is plasmodium falciparum?

protist (pathogen) that causes malaria

300

What was the favourite movie mentioned yesterday?

BRGvengers BRGZfinity war

400

translate to english from french:

je ne crois pas que vous avez compris ce que j'ai dit

I don't believe you understood what I said

500

A student prepares a buffer by mixing 250.0 mL of 0.200 mol L⁻¹ ethanoic acid (Ka=1.8×10−5K_a = 1.8\times10^{-5}Ka=1.8×10−5) with 250.0 mL of 0.200 mol L⁻¹ sodium ethanoate.

To this buffer, 0.0100 mol of solid sodium hydroxide is added and allowed to dissolve completely.

The resulting solution is then diluted to exactly 1.000 L and analysed using a colorimeter. The absorbance of the ethanoate ion at a particular wavelength is found to be exactly 0.602 in a 1.00 cm cuvette. Under these conditions, the molar absorptivity of the ethanoate ion is 1.50×103 L mol−1cm−11.50\times10^3\ \text{L mol}^{-1}\text{cm}^{-1}1.50×103 L mol−1cm−1.

Assuming all equilibria are established and all solutions behave ideally:

Question (8 marks)

""Determine the pH of the final solution.""

Why this is evil

To solve it, you must realise that:

1. The NaOH reacts quantitatively with the weak acid.
2. You must determine the new mole ratio in the buffer.
3. You must use the absorbance data to verify the final concentration of ethanoate using the Beer-Lambert Law.
4. You must recognise that dilution changes concentrations but not the acid/base mole ratio.
5. You must then apply the Henderson–Hasselbalch equation.
6. Any arithmetic error compounds through the entire problem.

This looks like a buffer question, but it secretly combines:

• Weak acids
• Buffer calculations
• Stoichiometry
• Beer-Lambert spectroscopy
• Dilution
• Equilibrium

pH=4.92