Chemistry Questions & Answers - Free Online Practice

511.

Petroleum is a non-renewable source of energy because it

is formed naturally

is cheap

can be recycled after use

cannot be regenerated once used up

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Correct answer is D

No explanation has been provided for this answer.

512.

A primary alkanol has a molecular mass of 60. What is the structural formula of the compound? [C= 12.0, H= 1.0, O= 16.0)

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Correct answer is B

Alkanols have the formula $C_{n}H_{2n+1}OH$ .

⇒ $12n + (1\times (2n+1)) + 16.0 + 1.0 = 60$

= (14n +18 = 60\)

$n = \frac{60-18}{14} = \frac{42}{14} = 3$

Hence, the alkanol is gotten by putting n=3,

= $C_{3}H_{7}OH$

513.

The real harmful effect of the release of chlorofluorocarbons into the atmosphere is that it eventually causes

excessive ultraviolet light from the sun to reach the earth surface

excessive release of infrared light from the sun to the earth surface

corrosive effect of the chemicals on humans and animals

acidic effect of chemicals on humans

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Correct answer is A

Chlorofluorocarbons are harmful to environment and living beings because it increases greenhouse gases in the environment which results in forming holes in the ozone layer.. And if this happens it will cause to an increase in the ultraviolet rays exposer, and which will make the earth's surface much hotter than usual.

514.

The IUPAC name for the compound $ClCH_{2}CH_{2}OH$ is

1- chloropropanol

2-chloropropanol

1-chloroethanol

2-chloroethanol

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Correct answer is D

The parent chain for the compound is $C_{2}H_{5}OH$ in which one of the hydrogen atoms is replaced by the Cl atom. Giving the chlorine the highest number while naming, we have 2- chloroethanol.