Biomolecules - Class 12 Chemistry - Chapter 10 - Notes, NCERT Solutions & Extra Questions
Renews every month. Cancel anytime
Your personal doubt-solving assistant
Chatterbot AI gives you 100% accurate answers to your questions in an instant.
Extra Questions - Biomolecules | NCERT | Chemistry | Class 12
What is the name of the compound with the formula $NF_3$, $CF_4$, and $NO$?
The compounds with the given formulas are named as follows:
$NF_3$: This compound consists of nitrogen and fluorine. The formula indicates one nitrogen atom and three fluorine atoms. The correct name is Nitrogen Trifluoride.
$CF_4$: This compound is made up of carbon and fluorine. There is one carbon atom and four fluorine atoms. Therefore, it is named Carbon Tetrafluoride.
$NO$: The formula shows one nitrogen atom and one oxygen atom. It is named Nitrogen Monoxide.
In summary:
$NF_3$ is Nitrogen Trifluoride
$CF_4$ is Carbon Tetrafluoride
$NO$ is Nitrogen Monoxide
What is the formula for $nitrogen dioxide$, $boron$ $trichloride$, and $sulfur$ $dichloride$?
The question asks for the chemical formulas of nitrogen dioxide, boron trichloride, and sulfur dichloride. Let's examine each compound to identify the correct formulas based on their names:
Nitrogen dioxide:
The name consists of two parts: "nitrogen" and "dioxide." The prefix 'di-' in dioxide indicates the presence of two oxygen atoms. Since there is no prefix before "nitrogen," it implies the presence of a single nitrogen atom. Therefore, the formula for nitrogen dioxide is:
$$ \text{NO}_2 $$Boron trichloride:
Here, the name includes "boron" and "trichloride." The prefix 'tri-' denotes three chlorine atoms. Again, the absence of a prefix before "boron" suggests a single boron atom. Thus, the formula for boron trichloride is:
$$ \text{BCl}_3 $$Sulfur dichloride:
The compound’s name "sulfur dichloride" contains the prefix 'di-', indicating two chlorine atoms. With no prefix before "sulfur," it is understood to contain one sulfur atom. Hence, the formula for sulfur dichloride is: $$ \text{SCl}_2 $$
In summary, the chemical formulas for the compounds are:
Nitrogen dioxide: $\text{NO}_2$
Boron trichloride: $\text{BCl}_3$
Sulfur dichloride: $\text{SCl}_2$
These formulas directly reflect the number of respective atoms as indicated by the prefixes (or lack thereof) in each compound's name.
To represent the formula for phosphorus pentachloride, nitrogen trifluoride, and carbon tetrafluoride, we can use the chemical symbols for each element along with the number of atoms present in the compound.
The formulas are as follows:
Phosphorus pentachloride: $PCl_5$
Nitrogen trifluoride: $NF_3$
Carbon tetrafluoride: $CF_4$
The provided question asks for the chemical formulas of phosphorus pentachloride, nitrogen trifluoride, and carbon tetrafluoride using the chemical symbols for each element and their respective counts in each molecule.
Chemical Formulas:
Phosphorus Pentachloride ($\mathbf{PCl_5}$)
Phosphorus (P): No prefix, indicating only one phosphorus atom.
Chlorine (Cl): The prefix 'penta-' signifies five chlorine atoms.
Formula: $PCl_5$
Nitrogen Trifluoride ($\mathbf{NF_3}$)
Nitrogen (N): No prefix, indicating only one nitrogen atom.
Fluorine (F): The prefix 'tri-' indicates three fluorine atoms.
Formula: $NF_3$
Carbon Tetrafluoride ($\mathbf{CF_4}$)
Carbon (C): No prefix, therefore there is one carbon atom.
Fluorine (F): The prefix 'tetra-' designates four fluorine atoms.
Formula: $CF_4$
Each formula clearly denotes the number of each type of atom present in these compounds, illustrated by the prefixes and the chemical symbols. These details allow us to accurately represent the molecular composition of each compound.
What is the formula for carbon monoxide, boron trifluoride, and dinitrogen tetroxide?
The chemical formulas for the compounds mentioned are derived from the composition and quantity of their respective elements based on their prefixes:
Carbon monoxide:
Contains carbon (C) and oxygen (O).
No prefix before 'carbon' indicates 1 carbon atom.
The prefix 'mono' before 'oxide' indicates 1 oxygen atom.
Therefore, the formula for carbon monoxide is: $$ CO $$
Boron trifluoride:
Consists of boron (B) and fluoride (fluorine, F).
No prefix before 'boron' means 1 boron atom.
The prefix 'tri' before 'fluoride' signifies 3 fluorine atoms.
Hence, the formula for boron trifluoride is: $$ BF_3 $$
Dinitrogen tetroxide:
Made up of nitrogen (N) and oxide (oxygen, O).
The prefix 'di' before 'nitrogen' denotes 2 nitrogen atoms.
The prefix 'tetra' (with a typo in the transcript as 'tetro') before 'oxide' represents 4 oxygen atoms.
Consequently, the formula for dinitrogen tetroxide is: $$ N_2O_4 $$
Summarizing the formulas:
Carbon monoxide: $ \textbf{CO} $
Boron trifluoride: $ \textbf{BF}_3 $
Dinitrogen tetroxide: $ \textbf{N}_2\textbf{O}_4 $
These compounds are composed by counting the number of each type of atom present as indicated by their respective prefixes in their chemical names.
The formulas for the mentioned compounds are:
Boron trichloride: $BCl_3$
Dioxygen difluoride: $O_2F_2$
Sulfur trioxide: $SO_3$
The formulas for the mentioned compounds are correctly noted with attention to the atomic composition and the chemical prefixes that indicate the quantity of each atom involved in the compounds.
Formulas for the compounds:
Boron Trichloride:
Chemical symbols: Boron (B), Chlorine (Cl)
Prefix "tri" in trichloride indicates that there are three chlorine atoms.
No prefix before boron suggests one boron atom.
Formula: $ BCl_3 $
Dioxygen Difluoride:
Chemical symbols: Oxygen (O), Fluorine (F)
Prefix "di" on both dioxygen and difluoride signifies there are two atoms of each element.
Formula: $ O_2F_2 $
Sulfur Trioxide:
Chemical symbols: Sulfur (S), Oxygen (O)
The prefix "tri" in trioxide reveals the presence of three oxygen atoms.
Since there's no prefix before sulfur, it denotes a single sulfur atom.
Formula: $ SO_3 $
In clear terms, these formulas are derived by recognizing the prefixes used (tri, di) which respectively tell the number of atoms: tri for three, and di for two, and applying these to the chemical symbols of each element from the periodic table. These compounds' compositions are crucial for understanding their chemical characteristics and reactivity.
Polystyrene is a/an
A) Copolymer
B) Addition Polymer
C) Condensation polymer
D) Elastomer
Answer: B) Addition Polymer
Explanation:
Polystyrene is a type of polymer that is formed by the addition polymerization of the monomer styrene. In this process, styrene molecules add to each other to form long chains, without any small molecules being released during the reaction. Thus, it falls into the category of addition polymers rather than copolymers, condensation polymers, or elastomers.
Which vitamin deficiency causes "Cheilosis" and "Digestive disorders"?
A. Thiamine
B. Ascorbic acid
C. Riboflavin
D. Pyridoxine
The correct answer is C. Riboflavin.
'Cheilosis' and 'Digestive disorders' are conditions associated with the deficiency of Vitamin B2, also known as Riboflavin.
Capping and tailing are carried out on mRNAs to:
A. Ensure protection from ribonucleases.
B. Ensure attachment to ribosomes for translation.
C. Ensure ease of transportation and identification.
D. All of the above.
The correct answer is D. All of the above.
Capping and tailing of nascent mRNA are crucial post-transcriptional modifications that provide several benefits:
Protection from ribonucleases: They safeguard the mRNA from degradation by enzymatic activities.
Attachment to ribosomes for translation: These modifications assist in the efficient recognition and binding of the mRNA to ribosomes, which is essential for protein synthesis.
Ease of transportation and identification: They facilitate the proper export of mRNA from the nucleus to the cytoplasm and aid in the mRNA's recognition by cellular machinery.
Overall, capping and tailing are essential for the stability, functionality, and efficient processing of mRNA before it is translated into proteins in the cytoplasm.
Nylon-2-nylon-6 is a
A. Biodegradable polymer
B. Copolymer
C. Polyamide
D. Non-biodegradable polymer
Nylon-2-nylon-6 can be best described by the following options:
A. Biodegradable polymer
B. Copolymer
C. Polyamide
Explanation:
Nylon-2-nylon-6 is classified as a biodegradable polymer, given its chemical composition derived from glycine and amino caproic acid.
Additionally, it is a copolymer because it is made by combining two types of monomers (glycine and amino caproic acid).
It is also categorized as a polyamide due to the presence of amide linkages in its chain structure that characterize polyamides.
The carbohydrates on the extracellular membrane form:
A) Glycocalyx
B) Sugar chains
C) Peptidoglycan
D) Glucose chain
The correct answer is Option A: Glycocalyx.
Explanation:
The Glycocalyx is a layer composed of carbohydrates that is found on the exterior of cells. These carbohydrates are attached to the proteins and lipids on the cell's surface, forming a vital component of the cell membrane. It plays a crucial role in cell recognition, protection, and adhesion.
Why are 12 molecules of water used as substrate?
The process of photosynthesis primarily involves the conversion of light energy into chemical energy, which is stored in glucose. The overall balanced chemical equation for photosynthesis is:
$$ 6 CO_2 + 12 H_2O + light \rightarrow C_6H_{12}O_6 + 6 O_2 + 6 H_2O $$
This equation clearly shows that for the synthesis of one glucose molecule, six molecules of carbon dioxide $(CO_2)$ and twelve molecules of water $(H_2O)$ are initially used.
During the light reactions of photosynthesis:
Water is split during the photolysis process, leading to the production of electrons, hydrogen ions, and oxygen.
Specifically, for every molecule of oxygen produced, two water molecules are consumed to provide the necessary electrons and protons required.
Furthermore, for the synthesis of NADPH, an essential molecule needed in the Calvin cycle (dark reactions), water acts as an electron donor. The conversion of NADP+ to NADPH utilizes electrons that are ultimately derived from the splitting of water molecules:
To produce two molecules of NADPH, two molecules of water are required. Hence, to generate the twelve NADPH molecules needed, a total of twelve water molecules are utilized.
Additionally, the light reactions produce ATP, contributing to the energy requirements of the Calvin cycle. This cycle uses the ATP and NADPH to convert the carbon dioxide into glucose. Thus, it can be concluded that a significant function of the twelve water molecules in photosynthesis is to supply electrons through their photolytic splitting, facilitating the formation of oxygen, ATP, and NADPH essential for synthesizing glucose.
Oxidation of one molecule of NADH gives
A) 3 ATP molecules
B) 12 ATP molecules
C) 1 ATP molecule
D) 8 ATP molecules
The correct answer is A) 3 ATP molecules.
Oxidation of one molecule of NADH results in the production of approximately 3 ATP molecules. More accurately, it is 2.5 ATP molecules based on more recent studies. The reason for this fractional value lies in the fact that ATP production is intricately linked to the chemiosmotic diffusion of protons across a proton gradient, rather than being the outcome of a straightforward reaction.
Southern Blotting uses a nitrocellulose membrane to absorb the DNA from the gel. What makes the DNA move towards the nitrocellulose membrane?
A. Movement of liquid in the gel tank towards the blotting paper.
B. Nitrocellulose membrane is positively charged.
C. Nitrocellulose membrane contains DNA probes to which DNA fragments attach.
D. The gel is placed above the membrane, and gravity pulls the DNA below to the membrane.
The correct answers are:
- A: Movement of liquid in the gel tank towards the blotting paper.
- B: Nitrocellulose membrane is positively charged.
In the Southern Blotting method, the setup includes a blotting paper positioned above the nitrocellulose membrane, which lies on top of the gel. The movement of fluid in the system is primarily upward due to capillary action, which also carries the DNA fragments upwards. Given that the DNA molecules are negatively charged, they adhere to the positively charged nitrocellulose membrane, thus enabling their transfer and subsequent analysis.
Keeping in view the "fluid mosaic model" for the structure of the cell membrane, which of the following statements is correct with respect to the movement of lipids and proteins from one lipid monolayer to the other (described as flip-flop movement)?
A) Both lipids and proteins can flip-flop.
B) While lipids can rarely flip-flop, proteins cannot.
C) While proteins can flip-flop, lipids cannot.
D) Neither lipids nor proteins can flip-flop.
The accurate answer is Option B: While lipids can rarely flip-flop, proteins cannot.
In the fluid mosaic model of cell membranes, flip-flop movement is an exception rather than the norm. Lipids occasionally perform this action, although it's rare. In contrast, proteins are generally unable to engage in flip-flop movements due to their size and complex structure.
Micelle formation is necessary for the intestinal absorption of:
A. Glycerol
B. Bile acids
C. Vitamin $B_{12}$
D. Vitamin D
Solution
The correct answer is D. Vitamin D.
Micelles play a crucial role in the absorption of fat-soluble vitamins by solubilizing them in the aqueous environment of the intestinal lumen. Among the options given, Vitamin D is fat-soluble and requires micelles for effective intestinal absorption.
- Glycerol, a product of lipid digestion, is water-soluble, so it does not require micelles for absorption.
- Although bile acids are essential components in micelle formation, they are absorbed via a specific $\mathrm{Na}^+$-dependent cotransporter in the ileum.
- Vitamin $B_{12}$ is water-soluble and is absorbed with the help of intrinsic factor rather than requiring incorporation into micelles.
Which of the following macronutrients are required for the synthesis of nucleic acids?
A) Phosphorus, magnesium, nitrogen
B) Phosphorus, potassium, nitrogen
C) Nitrogen, magnesium, calcium
D) Phosphorus, nitrogen, sulfur
The correct option is A) Phosphorus, magnesium, nitrogen.
- Phosphorus is essential because it forms part of the phosphate group in nucleic acids.
- Nitrogen is crucial as it is a component of the purine and pyrimidine bases in nucleic acids.
- Magnesium functions as an important co-factor for assorted enzymes, such as phosphorylase, which play roles in the synthesis of nucleic acids.
Substance having equivalent number of molecules as in 9 g of water is:
A. 12 g of Magnesium B. 12 g of Carbon C. 17 g of Ammonia D. 11 g of Carbon dioxide
To solve the question of finding the substance with the equivalent number of molecules as in 9 grams of water, we first need to determine how many moles of molecules are contained in 9 grams of water (H2O).
The molar mass of water is calculated as follows:
Hydrogen (H) has a molar mass of 1 g/mol, and since there are two hydrogens, that contributes $2 \times 1 = 2$ g/mol.
Oxygen (O) has a molar mass of 16 g/mol.
Adding together, the molar mass of water (H2O) is: $$ 2 + 16 = 18 \text{ g/mol} $$
Thus, 9 grams of water equates to: $$ \frac{9 \text{ g}}{18 \text{ g/mol}} = 0.5 \text{ moles} $$
Since each mole of any substance contains Avogadro's number ($N_A \approx 6.022 \times 10^{23}$ molecules/mol) of molecules, 9 grams of water contains about $0.5N_A$ molecules.
We need to find which among the options provided has the same number of molecules. Let's calculate the number of moles (and hence molecules) present in each option:
12 g of Magnesium (Mg)
Magnesium has a molar mass of 24 g/mol. $$ \frac{12 \text{ g}}{24 \text{ g/mol}} = 0.5 \text{ moles} $$ Hence, it also has $0.5N_A$ molecules.
12 g of Carbon (C)
Carbon has a molar mass of 12 g/mol. $$ \frac{12 \text{ g}}{12 \text{ g/mol}} = 1 \text{ mole} $$ This calculation results in $1N_A$, which is not equal to $0.5N_A$.
17 g of Ammonia (NH3)
The molar mass of NH3 (1 nitrogen + 3 hydrogens) is $14 + 3 = 17$ g/mol. $$ \frac{17 \text{ g}}{17 \text{ g/mol}} = 1 \text{ mole} $$ Like Carbon, ammonia also ends up having $1N_A$ molecules.
11 g of Carbon dioxide (CO2)
The molar mass of CO2 (1 carbon + 2 oxygens) is $12 + 2(16) = 44$ g/mol. $$ \frac{11 \text{ g}}{44 \text{ g/mol}} = 0.25 \text{ moles} $$ This results in $0.25N_A$ molecules.
Among all the options, 12 g of Magnesium is the only one that contains $0.5N_A$ molecules, which is equivalent to the number of molecules in 9 g of water. Therefore, the correct answer to the question is:
A. 12 g of Magnesium
The given molecule is used as an:
Insecticide
Antihistamine
Analgesic
Antacid
The correct option is C: Analgesic
The given molecular structure corresponds to aspirin, which is commonly used as an analgesic. Aspirin effectively reduces pain, fever, and inflammation by inhibiting the enzyme cyclooxygenase, which is involved in the synthesis of prostaglandins.
💡 Have more questions?
Ask Chatterbot AI