Share & grow the world's knowledge!
We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge.
An element ‘Z’ is highly reactive, reacts with oxygen to give a white solid, and cannot be obtained by reduction with carbon. (i) Name element ‘Z’. (ii) Explain the method used to extract ‘Z’ from its ore. (iii) Write the chemical equation involved in the extraction.
(i) Name element ‘Z’. Element ‘Z’ is Potassium (K) (or any alkali metal like Sodium, Na, depending on context). It is highly reactive, especially with oxygen. (ii) Explain the method used to extract ‘Z’ from its ore. Since Potassium is very reactive, it cannot be reduced by carbon. It is extracted uRead more
(i) Name element ‘Z’. Element ‘Z’ is Potassium (K) (or any alkali metal like Sodium, Na, depending on context). It is highly reactive, especially with oxygen.
(ii) Explain the method used to extract ‘Z’ from its ore. Since Potassium is very reactive, it cannot be reduced by carbon. It is extracted using electrolysis of its molten compound, usually potassium chloride (KCl).
(iii) Write the chemical equation involved in the extraction. Electrolysis of molten potassium chloride:
See lessAssertion (A): Carbon has a strong tendency to either loss or gain electrons to attain noble gas configuration. Reason (R): Carbon has 4 electrons in its outermost shell and has the tendency to share electrons with carbon or other elements.
ANSWER: [D] Explanation: A is false but R is true. Step 1 – Carbon’s behavior: Carbon has 4 valence electrons. To achieve noble gas configuration, it does not strongly lose or gain electrons because gaining 4 electrons or losing 4 electrons is difficult. Instead, it shares electrons to form covalentRead more
ANSWER: [D]
Explanation: A is false but R is true.
Step 1 – Carbon’s behavior:
Carbon has 4 valence electrons. To achieve noble gas configuration, it does not strongly lose or gain electrons because gaining 4 electrons or losing 4 electrons is difficult. Instead, it shares electrons to form covalent bonds.
Step 2 – Reason (R):
R is correct: Carbon has 4 valence electrons and tends to share electrons, forming covalent bonds with itself or other elements.
Step 3 – Relation:
See lessA is false (because carbon prefers sharing, not losing/gaining electrons).
R is true (carbon shares electrons).
When excess of carbon dioxide is passed through lime water, the milkiness disappears because [A] water soluble calcium carbonate converts to water soluble calcium bicarbonate. [B] insoluble calcium carbonate converts to water soluble calcium bicarbonate. [C] water soluble calcium carbonate converts to insoluble calcium bicarbonate. [D] insoluble calcium carbonate converts to insoluble calcium bicarbonate.
ANSWER: [B] Explanation: When CO₂ is first passed through lime water, Ca(OH)₂ reacts to form insoluble CaCO₃, which makes the solution milky. On passing excess CO₂, the CaCO₃ dissolves forming soluble Ca(HCO₃)₂, causing the milkiness to disappear.
ANSWER: [B]
Explanation: When CO₂ is first passed through lime water, Ca(OH)₂ reacts to form insoluble CaCO₃, which makes the solution milky. On passing excess CO₂, the CaCO₃ dissolves forming soluble Ca(HCO₃)₂, causing the milkiness to disappear.
See lessThe formulae of four organic compounds are shown below. Choose the correct option:
The correct answer is [C]. The reaction that converts alkenes into alkanes is called hydrogenation. In this process, hydrogen gas (H₂) is added to the carbon–carbon double bond of the alkene, converting it into a single bond, thereby forming an alkane. For hydrogenation to occur, specific conditionsRead more
The correct answer is [C]. The reaction that converts alkenes into alkanes is called hydrogenation. In this process, hydrogen gas (H₂) is added to the carbon–carbon double bond of the alkene, converting it into a single bond, thereby forming an alkane. For hydrogenation to occur, specific conditions are required: a metallic catalyst, usually nickel (Ni), must be present to speed up the reaction, and the reaction temperature should be maintained around 423 K. This process is widely used in the food and chemical industries.
See lessTake about 1-gram solid NaCl in a clean and dry test tube and set up the apparatus as shown in figure. Now, say that – (If climate is humid the gas evolved is passed through a guard tube containing):
ANSWER: [D] Explanation: During the preparation of hydrogen chloride gas, the gas is usually passed through the guard tube containing calcium chloride during humid climate, as calcium chloride is a good drying agent and absorbs moisture from the gas.
ANSWER: [D]
Explanation: During the preparation of hydrogen chloride gas, the gas is usually passed through the guard tube containing calcium chloride during humid climate, as calcium chloride is a good drying agent and absorbs moisture from the gas.
See less