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.
Alkenes can be manufactured by
the combustion of alkanes.
the cracking of hydrocarbons.
polymerization reactions.
addition of hydrogen to unsaturated vegetable oils.
Correct answer is B
Cracking is a chemical process in which larger hydrocarbon molecules are broken down into smaller and more useful ones. This process is commonly used in petroleum refining to convert heavy hydrocarbons into lighter fractions, including alkenes. During cracking, high-temperature and/or catalytic conditions are applied to break the long carbon chains of hydrocarbons into shorter ones. This process produces a mixture of products, including alkenes, which are unsaturated hydrocarbons containing carbon-carbon double bonds.
The following steps are scientific methods except
experimentation
problem identification
Analysis
Open-mindedness
Correct answer is D
From the given options, "Open-mindedness" is not a specific step in the scientific method. Open-mindedness is a general mindset that scientists should have throughout the entire process. It involves being receptive to new ideas, evidence, and interpretations, which helps scientists avoid biases and reach more accurate conclusions.
Which of the following reactions represents the hydrolysis of an alkanoate?
\(CH_3COOH + OH^- ⇌H^+⇌ CH_3COO^- + H_2O\)
\(CH_3COOH + C_2H_5OH ⇌H^+⇌ CH_3COOC_2H_5 + H_2O\)
\(CH_3COOC_2H_5 + H_2O ⇌H^+⇌ CH_3COO^- + CH_3CH_2OH\)
\(CH_3COOCH_2CH_3 + H_2O ⇌H^+⇌ CH_3COOH + CH_3CH_2OH\)
Correct answer is D
The hydrolysis of an alkanoate is the reaction of an alkanoate with water to form a carboxylic acid and an alcohol. The correct reaction is:
\(CH_3COOC_2H_5 + H_2O ⇌H^+⇌ CH_3COOH + CH_3CH_2OH\)
The following statements are correct except
energy is released when liquids change to solids.
carbon atoms in gaseous methane are further apart than those in solid diamond.
there is large decrease in the volume of a solid metal when pressure is applied to it.
particles move faster in the gaseous state than in the liquid state.
Correct answer is C
In general, solids are relatively incompressible compared to liquids and gases. When pressure is applied to a solid, there is typically only a small change in volume. Solids have tightly packed particles with strong intermolecular forces, making them less responsive to changes in pressure. Liquids and gases, on the other hand, can undergo larger volume changes in response to pressure.
40
120
65
30
Correct answer is D
Molar mass of \(C_2H_4O_2\),= (12 × 2) + (1 × 4) + (16 × 2)= 60 g/mol
Vapour density = RMM/2
=60/2=30
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