You have been appointed as an environmental engineer in a refinery plant operating in south africa which produces various different types of waste. suggest two (2) methods of 4.1 waste management for each type of waste produced: 4.1.1 sludge produced as a byproduct from the process. (2) (2) 4.1.2 sewage from the bathrooms and change-house. (2) 4.1.3 waste from the canteen such as food, plastics, cans, etc. unacceptable forms of waste management for rubber material from old tyres? (i. e. (2) 4.1.4 what methods should not be used to manage rubber material from old 22 chp3601/101/0/2019 2. describe the process of condensation as a mechanism for cleaning air; include in your (10) explanation a description of the two types of condensers. 4.3. a 3.0 x 105 cm3 sample of air was found to contain 15 ug of no2. the temperature and pressure were 21°c and 102.421 kpa when the sample was taken. 4.3.1 what was the no2 concentration in ppm (molecular weight of no2 46 g/mol)? (5) 4.3.2 is the level of no2 in the air sample higher or lower than the allowable range for people and animals? (2) 4.3.3 state the harmful effects of no2 gas on people and animals

answer : the correct answer is 2) hno₃ and naoh .

arrhenius concept of acid and base :

acid :

according to arrhenius acid are those which release h⁺ or hydronium ion (h₃o⁺) in aqueous solution .

example : hcl +h₂o ↔ h₃o⁺ + cl⁻

hcl is giving h₃o⁺ ion in water , hence it is an arrhenius acid .

base :

according to arrhenius , bases are those which releases oh⁻ ions in aqueous solution .

example : koh (aq) ↔ k⁺ + oh⁻

since koh is producing oh⁻ ions hence , it is an arrhenius base .

checking the options :

1) ch₃oh and naoh :

ch₃oh is known as methanol , an organic compound , which is neutral compound . the dissociation of ch₃oh is negligible . it is very very weak acid (ka = 3.2 * 10 ⁻¹² ) .

naoh being ionic gives na⁺ and oh⁻ ions in aqueous solution as :

naoh ↔ na⁺ + oh⁻ . hence it is an arrhenius base

it can be concluded that ch₃oh and naoh is not arrhenius acid and base.

2) hno₃ and naoh :

hno₃ is an ionic compound which gives ions h⁺ and no₃⁻ ion in aqueous solution as:

hno₃ + h₂o ↔ h₃o⁺ + no₃⁻

since it is giving h⁺ ion . hno₃ is arrhenius acid .

naoh being ionic gives na⁺ and oh⁻ ions in aqueous solution as :

naoh ↔ na⁺ + oh⁻

. hence it is an arrhenius base .

it can be said that hno₃ and naoh are arrhenius acid and base.

3) ch₃oh and hcl

as discussed ch₃oh is neutral compound .

while hcl in aqueous solution dissociates to give h⁺ and cl⁻ ions as :

hcl + h₂o→ h₃o⁺ + cl⁻ . so hcl is arrhenius acid .

hence , ch₃oh and hcl are not arrhenius acid and base.

4) hno₃ and hcl :

hno₃ as discussed gives h⁺ in aqueous solution , while hcl also gives h⁺ in aqueous solution .

hence both hno₃ and hcl are arrhenius acid they are not acid and base .

so the arrhenius acid and base are 2) hno₃ and naoh.