Processing math: 100%
Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

596.

Ethene is produced from ethanol by

A.

decomposition

B.

hydrolysis

C.

ozonolysis

D.

dehydration

Correct answer is D

Ethene can be gotten from the dehydration of ethanol in the presence of excess  H2SO4 or H3PO4.

597.

Consider the following reaction equation: Br2+2KI2KBr+I2. Bromine is acting as

A.

an oxidizing agent

B.

a reducing agent

C.

an acid

D.

a base

Correct answer is A

No explanation has been provided for this answer.

598.

An organic compound has the empirical formula CH2. If its molar mass is 42gmol1, what is its molecular formula?  (C = 12.0, H = 1.0)

A.

C2H4

B.

C3H4

C.

C3H6

D.

C4H8

Correct answer is C

Given the molecular formula, CH2.

The empirical formula will be (CH2)n= 42

(12+(2×1))n=42

14n=42

n = 3, hence the empirical formula is C3H6

599.

In which of the following compounds does hydrogen form ionic compounds?

A.

CH4

B.

HCl

C.

NH3

D.

NaH

Correct answer is D

The bonding between a non-metal and a metal is an ionic bonding. In metal hydrides, Hydrogen takes on the ionic charge of -1, hence forming an ionic bond with the metals.

600.

A reaction is endothermic if the

A.

reaction vessel feels cool during the reaction

B.

enthalpy change is negative

C.

bond forming energy exceeds bond breaking energy

D.

heat of formation of reactants exceeds heat of formation of products

Correct answer is A

Endothermic reactions absorb heat from their surroundings during the reaction process. This means that in the course of the reaction the vessel being used in the reaction will be cool in the process.