The p-Block Elements: Class 11 Chemistry Q&A
20 free answers on The p-Block Elements (Chemistry) for Class 11 students, across CBSE, ICSE and State boards. Includes questions such as “C2H5OH → C2H5Br (Ethyl bromide)”, “What is CuSO4 used for?”, “How do you write copper sulphate?”
Question & Answer
Questions
- ChemistryClass 11CBSE
C2H5OH → C2H5Br (Ethyl bromide)
React ethanol with HBr (or PBr₃). The -OH group is protonated, making water a leaving group, and Br⁻ substitutes via SN2.
- ChemistryClass 11CBSE
What is CuSO4 used for?
Copper sulfate is used as a fungicide, herbicide, algaecide, wood preservative, laboratory reagent, and in various industrial processes. Detailed Explanation:Major Applications: Agriculture: Fungicide for crops (Bordeaux mixture) Treatment for plant deficiencies Animal feed supplement (trace amounts) Water Treatment: Algae control in ponds and pools
- ChemistryClass 11CBSE
How do you write copper sulphate?
Copper sulphate is written as CuSO4 in chemical formula notation, or copper(II) sulfate in word form. Detailed Explanation:Correct Ways to Write It: Chemical Formula: CuSO₄ (with subscript 4) CuSO4 (without subscript formatting) Word Forms: Copper(II) sulfate (American English) Copper(II) sulphate (British English) Cupric sulfate (older nomenclat
- ChemistryClass 11CBSE
What is the proper name for CuSO4?
The proper IUPAC name for CuSO4 is copper(II) sulfate, with the systematic name being copper(2+) sulfate. Detailed Explanation:Official Nomenclature: IUPAC systematic name: Copper(II) sulfate or copper(2+) sulfate Common chemical name: Cupric sulfate Formula name: CuSO4 The "(II)" or "(2+)" indicates copper's oxidation state, which is essential for distingui
- ChemistryClass 11CBSE
Is CuSO4 a base or acid?
CuSO4 is neither a base nor an acid in the traditional sense; it's a salt that produces slightly acidic solutions when dissolved in water. Copper sulfate is classified as a salt formed from: A strong acid (sulfuric acid, H₂SO₄) A weak base (copper hydroxide, Cu(OH)₂) When dissolved, CuSO4 creates a weakly acidic solution (pH around 3-4) because: Copper ions hydrolyze: Cu²⁺ + H₂O → Cu(OH)⁺ + H⁺ This releases hydrogen io
- ChemistryClass 11CBSE
How is CuSO4 formed?
Copper sulfate forms through chemical reactions between copper-containing substances and sulfuric acid or through oxidation of copper sulfide minerals. Detailed Explanation:Common Formation Methods: Copper + Sulfuric Acid (with oxidizer): Cu + H₂SO₄ + O₂ → CuSO₄ + H₂O Copper Oxide + Sulfuric Acid: CuO + H₂SO₄ → CuSO₄ + H₂O Industrial Production:</st
- ChemistryClass 11All
Is COOH an alcohol?
No, COOH is not an alcohol. It is a carboxyl group, which defines carboxylic acids. While it contains an –OH component, that hydroxyl group is chemically bonded to a carbonyl carbon, giving it very different properties from alcohols. Alcohols have a standalone –OH group attached to a carbon atom without a double-bonded oxygen. This structural difference explains why carboxylic acids are acidic, while alcohols are generally neutral. In practice, this distinction affects boi
- ChemistryClass 11All
What is the molar mass of urea?
The molar mass of urea is approximately 60.06 g/mol. This is calculated by adding the atomic masses of all atoms in the formula: carbon (12.01) + oxygen (16.00) + nitrogen (14.01 × 2) + hydrogen (1.01 × 4) = 60.06 g/mol.
- ChemistryClass 11All
What is the name of H₂NCONH₂?
H₂NCONH₂ is the chemical name for urea, also known as carbamide. This notation is yet another way to represent the molecular structure, showing the two amine groups (H₂N) bonded to a carbonyl carbon.
- ChemistryClass 11All
What is the chemical formula for urea?
The chemical formula for urea is CH₄N₂O or CO(NH₂)₂. This organic compound consists of one carbon atom, four hydrogen atoms, two nitrogen atoms, and one oxygen atom. The structural formula shows a carbonyl group (C=O) bonded to two amino groups (NH₂).
- ChemistryClass 11All
Is baking soda the same as ammonia?
No, baking soda (sodium bicarbonate, NaHCO₃) and ammonia (NH₃) are completely different chemical compounds. While both are alkaline and used for cleaning, they have different chemical structures, properties, and applications. Baking soda is much milder and safer to handle than ammonia.
- ChemistryClass 11All
What are the uses of ammonia?
Ammonia has diverse applications including fertilizer production (its largest use, accounting for about 80% of production), refrigeration systems, household and industrial cleaning products, water treatment, pharmaceutical manufacturing, and as a feedstock for producing plastics, explosives, and synthetic fibers. It's also being explored as a carbon-free fuel.
- ChemistryClass 11All
What is the smell of ammonia?
Ammonia has a sharp, pungent, and suffocating odor that's often described as similar to cleaning products or cat urine. The smell is highly distinctive and can be detected at very low concentrations (around 5 parts per million). Many people find it unpleasant and irritating to the nose and throat.
- ChemistryClass 11All
What is the cheapest way to produce ammonia?
The Haber-Bosch process remains the most economical method for large-scale ammonia production, using natural gas as a hydrogen source. However, costs vary based on energy prices and feedstock availability. Emerging technologies using renewable energy and water electrolysis are being developed but aren't yet cost-competitive at scale.
- ChemistryClass 11All
What is the largest source of ammonia?
Industrial production through the Haber-Bosch process is the largest source of ammonia globally, producing over 170 million tons annually. This process combines nitrogen from the air with hydrogen (typically from natural gas) under high pressure and temperature. Naturally, bacterial decomposition of organic matter is the primary source in ecosystems.
- ChemistryClass 11All
How is ammonia made naturally?
Ammonia is produced naturally through the breakdown of organic matter containing nitrogen. Bacteria in soil decompose dead plants, animals, and waste materials, releasing ammonia as part of the nitrogen cycle. It's also produced in smaller amounts by certain bacteria that fix atmospheric nitrogen and through volcanic activity.
- ChemistryClass 11All
What is the pH of ammonia?
Ammonia is basic (alkaline) with a pH typically ranging from 11 to 12 when dissolved in water. Pure ammonia gas doesn't have a pH, but when it dissolves in water to form ammonium hydroxide, it creates an alkaline solution that can neutralize acids.
- ChemistryClass 11All
What is NH₄₂O called?
The correct formula you're likely referring to is (NH₄)₂O, which is ammonium oxide. However, this compound is unstable and rarely exists in pure form. You might also be thinking of ammonia water (aqueous ammonia), which is ammonia dissolved in water.
- ChemistryClass 11All
Is NH₄ ammonia or NH₃?
NH₃ is ammonia, while NH₄⁺ (ammonium) is the ionic form that results when ammonia accepts a proton. When ammonia dissolves in water, it can form ammonium ions (NH₄⁺), but the pure compound ammonia itself is always NH₃. The two are related but chemically distinct.
- ChemistryClass 11All
What is the basic formula of ammonia?
The basic chemical formula of ammonia is NH₃, which consists of one nitrogen atom bonded to three hydrogen atoms. This is a simple compound that exists as a colorless gas at room temperature with a distinctive pungent odor.