Science Olympiad Test: Carbon and Its Compounds- 2 - Class 10 MCQ

The electron dot structure of water is:

Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outermost (valence) electrons, atoms can fill up their outer electron shell and gain stability. Nonmetals will readily form covalent bonds with other nonmetals in order to obtain stability, and can form anywhere between one to three covalent bonds with other nonmetals depending on how many valence electrons they possess.

The equation for the reaction between sodium and ethanol can be written as:
2CH₃​CH_2​OH + 2Na → 2CH₃​CH_2​ONa + H₂​
Therefore, the products formed are sodium ethoxide and hydrogen.

A soap molecule is a sodium or potassium salt of long-chain carboxylic acid. It is composed of two sections, i.e., a long hydrocarbon tail and a negatively charged head. The hydrocarbon tail is hydrophobic, i.e., insoluble in water and repelled by water while the polar end is soluble in water and hydrophilic in nature. Because the hydrophobic tail oil and grease is trapped inside a micelle. The hydrophobic head makes the outer surface of the micelle. Hence micelle is easily washed by water.

Vinegar is a dilute aqueous solution of ethanoic acid. The main component of vinegar is acetic acid, which gives a sour taste and pungent aroma. Acetic acid (CH₃COOH), also called ethanoic acid, is the most important of the carboxylic acids. Ethanoic acid is used as a solvent for the production of camphor and cooking material.

Carbon is found in the atmosphere as carbon dioxide gas in the air. Carbon can also be found in the earth’s crust in the form of carbonates. It can also be found in fossil fuels, organic molecules, cotton, wood and wool, among other things.

Benzene- C₆H₆ has alternate carbon-carbon single and double bonds.

• Ethanol + Methanol​ is denatured alcohol.
• Denatured alcohol is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption.
• The term denatured alcohol refers to alcohol products adulterated with toxic and/or bad tasting additives (e.g., methanol, benzene, pyridine, castor oil, gasoline, isopropyl alcohol, and acetone), making it unsuitable for human consumption.
• The most common additive used is methanol (5–10%), giving rise to the term methylated spirits. Denatured alcohol is used as a lower-cost solvent or fuel for home-scale or industrial use.

General Molecular formula of alkene-C_n​H_2n​
For 5C the molecular formula of alkene is -C_5​H_10​
And the structural formula can be shown as below:
CH₃ ​− CH = CH − CH_2​ − CH_3​

• Alcohols contain a hydroxyl functional group (-OH). The general molecular formula for alcohol is C_nH_2n+1OH.
• In propanol (C₃H₇OH), the functional group present is an alcohol (−OH) group.
• In propanone((CH3)2CO), the functional group present is a ketone (−C=O) group.
• In propanoic acid (C₂H₅COOH), the functional group present is a carboxylic acid (COOH), group 
• In ethanal (CH₃CHO), the functional group present is an aldehyde(−CHO) group.
• In propanal (C₂H₅CHO), the functional group present is an aldehyde(−CHO) group.

In Nitrogen molecule, each nitrogen atom has 5 valence electrons and there is a triple bond between the two nitrogen atoms. Thus, the correct electron dot structure is; 

Fats are formed when oils are treated with hydrogen in the presence of a palladium or nickel catalyst. Because hydrogen is added to oil by reducing agents palladium or nickel, this is an instance of an addition reaction.
Addition reaction: An addition reaction is a chemical reaction wherein two or more reactants come together to form a larger single product. Hydrochlorination of propane for which the equation is
CH₃CH = CH₂ + HCl → CH₃C⁺HCH₃ + Cl⁻ → CH₃CHClCH₃

In the alkyne series, there is a triple bond between the carbon atoms. The first member of the alkyne series is ethyne with two carbon atoms bonded by a triple bond as follow; 
HC ≡ CH.

• While cooking, if the bottom of the vessel is getting blackened on the outside, it means that the fuel is not burning completely. 
• Sometimes, due to lack of oxygen, the fuel does not burn completely.
• When the fuel does not burn completely then a sooty flame appears which makes the bottom of the utensil black.
• At the point when fuel doesn't consume appropriately, it starts to form incomplete burning fumes or black fumes that store on the base surface of the pot.

• In organic chemistry, heteroatoms are the ones that are not carbon or hydrogen.
• Molecules formed by only one type of atom are known as Homo-atomic molecules. For example, H₂, N₂, P₄ etc.
• Molecules formed by different types of atoms are known as Heteroatomic molecules. For example, CO₂, NO₂, CH₄, HCl etc.