Question

mod resource/contern ms for ench of the following , electricity O2 (g) NaOH(aq) HCl (aq) (a) Decomposition: (b) Combination: NaCl() SO2(g) + Nici faq) + + → + → ble replacement: Zn (s) → (d) Single replacement: 2. Which of the following are RedOx reactions? Write half equations and state the oxidizing and reducing agents for the RedOx reactions, (a) (b) AgNO3(aq) + NaCI(aq) → AgCl(s) + NaNO3(oq) 6 Li(s) + N2(g) → 2 LiaN(s) 3. When ethanol is ingested and metabolized in the liver, it is first converted to acetaldehyde, and then to acetic acid, as shown in the Lewis structures below: H O: HO ばH Ethanol Acetaldehyde Acetic acid (a) Is the conversion of ethanol to acetaldehyde oxidation or reduction? Justify (b) Is the conversion of acetaldehyde to acetic acid oxidation or reduction? Justify. 4. State whether each of the following refers to a saturated or unsaturated solution: 68g of a salt is added to 150g of HO at 20°C. (The salt has a solubility of 32g of salt in 100g of water at 20-C) 5. A solution is prepared by dissolving 22 0g of NaOH in 118.0g of water. The NaOH solution has a density of 1.15 g/mL (a) (b) (c) (d) (e) What is the mass percent (m/m) of the NaOH solution? What is the total volume (mL) of the solution? What is the molarity (M) of the solution? How many moles of solute are in 50mL of solution? What is the final volume, in mL, when 25.0mL of the NaOH solution is diluted to 0.100M?

2 and 3

Answer 1

2)

REDOX implies reduction/oxidaiton pairs:

Reduction = species that GAINS electrons

Oxidation = process in which a specie will LOSS electrons

Reducing agent = The species that favors reduction, i.e. it will oxidize in order to reduce another species

Oxidizing agent = The species that favors oxidation, i.e. it will reduce in order to oxidise another species

then...

a)

Ag goes from +1 in AgNO3, to +1 in AgCl

NO3- remains -1

Na goes from +1 in NaCl, and +1 in NaNO3

Cl goes from -1 in NaCl, remians -1 in AgCl

there is no redox

b)

Li goes from 0 in Li(s) to +1 in Li3N

N goes from 0 in N2(g) to -3 in LiN3

there is redox reaction!

Li(s) = Li+ + e-

2N2(g) + 6e- = 2N-3

Q3.

ethanol is being oxidized, since C-OH is less oxidize d( oxidation number) than C=OH, then COOH gets every time more oxidized

b)

still is a further oxidation, aldehyde group to acid group is addition of oxygens, by definition, it is getting oxidized (oxygenated)