c) Name two major impurities in bauxite.

Muda ($t$) = $3 \text{ hours} = 3 \times 60 \times 60 \text{ s} = 10800 \text{ s}$
Mkondo ($I$) = $5.0 \text{ A}$

$$Q = I \times t = 5.0 \text{ A} \times 10800 \text{ s} = 54000 \text{ C}$$

Kutoka mlinganyo wa kathodi, 1 mol ya $\text{Ag}$ huwekwa na 1 mol ya elektroni.
Hivyo, moli za $\text{Ag}$ = moli za elektroni $\approx 0.559585 \text{ mol}$.
Masi ya molar ya $\text{Ag}$ = $108 \text{ g/mol}$.

$$\text{Masi ya Ag} = \text{Moli za Ag} \times \text{Masi ya molar ya Ag}$$ $$\text{Masi ya Ag} = 0.559585 \text{ mol} \times 108 \text{ g/mol} \approx 60.435 \text{ g}$$

Masi ya fedha iliyowekwa ni $\boxed{\text{60.44 g}}$.

17. Kiwanja chenye fomula ya jumla M(OH)₃ humenyuka kama inavyoonyeshwa na mlinganyo hapa chini.
$\text{M}(\text{OH})_3(\text{s}) + \text{OH}^-(\text{aq}) \to \text{M}(\text{OH})_4^-(\text{aq})$
$\text{M}(\text{OH})_3(\text{s}) + 3\text{H}^+(\text{aq}) \to \text{M}^{3+}(\text{aq}) + 3\text{H}_2\text{O}(\text{l})$

a) Jina gani hupewa viwanja vinavyoonyesha tabia kama M(OH)₃ katika miitikio miwili?
Viwanja vinavyoweza kumenyuka kama asidi na besi huitwa amphoteric.

b) Taja elementi mbili ambazo hidroksidi zao huonyesha tabia kama ile ya M.

• Aluminium (Al)
• Zinki (Zn)

18. a) Eleza sheria ya Graham ya usambaaji.
Sheria ya Graham ya usambaaji inasema kwamba kiwango cha usambaaji au utoaji wa gesi ni kinyume sawia na mzizi wa mraba wa masi yake ya molar.

b) Masi za molar za gesi W na X ni 16.0 na 44.0 mtawalia. Ikiwa kiwango cha usambaaji wa W kupitia nyenzo yenye vinyweleo ni 12cm³s⁻¹, kokotoa kiwango cha usambaaji wa X kupitia nyenzo hiyo hiyo.

$$\frac{R_W}{R_X} = \sqrt{\frac{M_X}{M_W}}$$

Ambapo $R$ ni kiwango cha usambaaji na $M$ ni masi ya molar.

$R_W = 12 \text{ cm}^3\text{s}^{-1}$
$M_W = 16.0$
$M_X = 44.0$

$$\frac{12}{R_X} = \sqrt{\frac{44.0}{16.0}}$$

$$\frac{12}{R_X} = \sqrt{2.75}$$ $$\frac{12}{R_X} \approx 1.6583$$ $$R_X = \frac{12}{1.6583} \approx 7.236 \text{ cm}^3\text{s}^{-1}$$

Kiwango cha usambaaji wa X ni $\boxed{\text{7.24 cm}^3\text{s}^{-1}}$.