REVISION -Q.309- IAS 2019 PRELIMS

REVISION  -Q.309- IAS 2019 PRELIMS

LINK : http://www.upsconlineacademy.net/IAS-FRAMED-QUESTIONS.html

FRAMED FROM INDIAN EXPRESS

Q.309 Consider the following statements :

1. Foods containing carotene (Vitamin A) or cooking oils are safe to be cooked in a microwave

2. Thermocol plates are poor barrier to oxygen and water vapor and has a relatively high melting point

Select the correct answer using the codes given below :

A) Only 1

B) Only 2

C) Both are correct

D) Both are incorrect

Ans. D

Thermocol plates:-

It is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and rather brittle. It is an inexpensive resin per unit weight.

It is a rather poor barrier to oxygen and water vapor and has a relatively low melting point.

Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year.

Polystyrene can be naturally transparent, but can be colored with colorants.

Uses include protective packaging (such as packing peanuts and CD and DVD cases), containers (such as "clamshells"), lids, bottles, trays, tumblers, disposable cutlery.[5] and in the making of models.

Polystyrene is very slow to biodegrade and is therefore a focus of controversy among environmentalists.

It is increasingly abundant as a form of litter in the outdoor environment, particularly along shores and waterways, especially in its foam form, and also in increasing quantities in the Pacific Ocean.

Polystyrene is chemically very inert, being resistant to acids and bases but is easily dissolved by many chlorinated solvents, and many aromatic hydrocarbon solvents. Because of its resilience and inertness, it is used for fabricating many objects of commerce. It is attacked by many organic solvents, which dissolve the polymer. Foamed polystyrene is used for packaging chemicals.

Like all organic compounds, polystyrene burns to give carbon dioxide and water vapor.

Polystyrene, being an aromatic hydrocarbon, typically combusts incompletely as indicated by the sooty flame.

Polystyrene is generally non-biodegradable.

Polystyrene is commonly used in containers for food and drinks. The styrene monomer (from which polystyrene is made) is a cancer suspect agent

Another Japanese study conducted on wild-type and AhR-null mice found that the styrene trimer, which the authors detected in cooked polystyrene container-packed instant foods, may increase thyroid hormone levels

Whether polystyrene can be microwaved with food is controversial. Some containers may be safely used in a microwave, but only if labelled as such.[67] Some sources suggest that foods containing carotene (Vitamin A) or cooking oils must be avoided

Like other organic compounds, polystyrene is flammable.