NTSE Test: Carbon & Its Compounds - Class 10 MCQ

Ethane with molecular formula C₂H₆ has seven covalent bonds. 6 bonds between C-H and one is between C-C.

Key Points:
- Butanone is a four-carbon compound.
- We need to identify the functional group present in butanone.
Explanation:
1. Butanone is a four-carbon compound, which means it contains four carbon atoms.
2. To identify the functional group present in butanone, we need to look for any specific groups attached to the carbon atoms.
3. The functional group in butanone is a ketone group.
4. A ketone is a carbonyl group (C=O) attached to two carbon atoms.
5. In butanone, the carbonyl group is attached to the second carbon atom, making it a ketone.
6. Therefore, the correct answer is C: Ketone.
Answer: C: Ketone

The blackening of the bottom of the vessel while cooking indicates:
1. Incomplete combustion:
- When the bottom of the vessel gets blackened, it suggests that the fuel is not burning completely.
- Incomplete combustion occurs when there is insufficient oxygen supply for the combustion process.
- The lack of oxygen causes the fuel to produce soot, which then accumulates on the bottom of the vessel, resulting in blackening.
2. Insufficient ventilation:
- Another possible reason for the blackening of the vessel is inadequate ventilation in the cooking area.
- Insufficient ventilation can lead to incomplete combustion as the supply of fresh air is restricted.
- Without proper airflow, the fuel cannot burn efficiently, resulting in the formation of soot on the vessel.
3. Improper fuel quality:
- The quality of the fuel used for cooking can also contribute to the blackening of the vessel.
- If the fuel is damp or wet, it may not burn properly, leading to incomplete combustion.
- Wet fuel can release more smoke and soot, which can then settle on the vessel's bottom.
4. Incorrect cooking technique:
- The way cooking is being done can also be a factor in the blackening of the vessel.
- If the flame is too high or the heat source is concentrated on one spot, it can cause uneven heating and result in blackening.
- It is essential to ensure that the heat is evenly distributed and controlled to prevent the bottom of the vessel from blackening.
In conclusion, the blackening of the bottom of the vessel while cooking indicates incomplete combustion, insufficient ventilation, improper fuel quality, or incorrect cooking techniques. To avoid this, it is important to ensure proper ventilation, use dry fuel, maintain an even heat distribution, and adjust the cooking technique accordingly.

A covalent bond is formed by mutual sharing of electrons between the 2 atoms.

Alkyl halides are polar in nature, but they are almost insoluble in water. They can neither form Hydrogen bond nor they can break hydrogen bond between water molecules.

Benzene is C₆H₆ an aromatic compound in the form of a closed ring. It contains alternate double and single bond.

In benzene each carbon is bonded with other carbon and hydrogen. So, for each carbon there will be two sigma bonds, one with other carbon and another one is with hydrogen. So, now we can calculate the single bonds => 6*2= 12 
And when we come to the no. of pi bonds in each carbon in Benzene there will be one hybridized orbital that will overlap with other carbon axially to form pi bonds. There will be 6 carbons in benzene, so=> 6/2=3 
Hence, we can say there are 3 double bonds in benzene. 

Methane + ol = Methanol
Methane + al = Methanal

Graphite is composed of layers of carbon atoms that are arranged in 6 - membered hexagonal rings. These rings are attached to one another on their edges. Layers of fused rings can be modeled as an infinite series of fused benzene rings.

Graphite has a hexagonal sheet structure in which every carbon atom is bonded to 3 other carbon atoms and the adjacent layers are arranged together by weak van der waal forces of attraction. 
The gap between the adjacent layers makes it soft and slippery.

Alkenes contain C-C double bond whereas alkynes contain C-C triple bond.

The general formula of monohydric alcohols is C_nH2_n+1OH where n = 1, 2, 3… etc.. or R-OH where R is any alkyl group.
Alcohols are formed by replacement of 1 hydrogen atom from hydrocarbons.

Ethanol is used as the important ingredient in manufacturing of wine, beer and other brewerie products.

Vinegar is an aqueous solution of acetic acid. Vinegar typically contains 5–8% acetic acid by volume.

Ethanol is neutral in nature as it shows no effect on litmus paper.But here it is acting as an acid as,Na is highly reactive.

Ethanol + methanol leads in formation of denatured alcohol. Methanol is added to make industrial alcohol unfit for drinking.

Option ( a) Na metal is the correct answer because other options ( b) ,( c) and ( d) are used to distinguish ethanol from ethanoic acid.

C₁₇H₃₅COOC₂H₅ + NaOH → C₁₇H₃₅COONa + C₂H₅OH

Detergents are sodium and potassium salts of Sulphonic acids. Thus detergents gave Sulphonic group instead of Carboxylic group. The detergents don't form precipitate with these metal ions.

When either calcium sulphate or magnesium bicarbonate or calcium chloride is dissolved in water, hard water is obtained. Hard water is due to presence of sulphates, chlorides or bicarbonates of magnesium and calcium in water. 

Ethanol is firstly oxidized to acetaldehyde and the acetaldehyde is then oxidized to acetic acid. This reaction is considered as a green catalytic process for the only reduction product is water.

 

Soaps are sodium or potassium salts of long chain fatty acids. When triglycerides in fat / oil react with aqueous NaOH or KOH, they are converted into soap and glycerol. This is called alkaline hydrolysis of esters. Since this reaction leads to the formation of soap, it is called the saponification process.