Explanation

• Tautomerism is the interconversion of two isomers by shifting a hydrogen atom and double bond.
• It usually occurs in compounds like alkenes, carbonyls, etc.
• Correct type shown in: CH3–CH=CH–CH3 ⇌ CH3–CH2–C–CH3

Last verified on 05-06-2026

Explanation

• Carboxylic acids show a strong C=O stretching peak in IR spectroscopy.
• This peak appears around 1700–1725 cm⁻¹.
• The most typical value is near 1710 cm⁻¹.
• It is a key characteristic of carbonyl groups.

Last verified on 05-06-2026

Explanation

• The teacher said that the sun rises in the east.
• The sentence is in direct speech, so it changes to indirect speech using “that”.
• Universal truth (sun rises in the east) remains in present simple tense.
• No change in meaning or tense is needed for scientific facts.

Last verified on 05-06-2026

Explanation

• The given sentence is in active polite request form (“Could you help me…?”).
• In passive voice, object (me) becomes subject → I.
• So it correctly changes to: “Could I be helped, please?”

Last verified on 05-06-2026

Explanation

• Enforce means to make sure a law is obeyed or applied properly.
• The sentence implies the king wanted the law to be strictly implemented.

Last verified on 05-06-2026

Explanation

• A seamstress is a woman who makes or repairs clothes professionally.
• The word is related to stitching, tailoring, and sewing work.

Last verified on 05-06-2026

Explanation

• Harmony means ہم آہنگی
• Discord means اختلاف
• Riot means فساد

Last verified on 05-06-2026

Explanation

• “Undergone” means experienced or suffered something difficult.
• The sentence suggests Hyder has experienced more strain and anxiety than others.
• So “has undergone more strain and anxiety” fits grammatically and logically.

Last verified on 05-06-2026

Explanation

• Gratis means something given without payment or free of cost.
• It is commonly used in formal or academic language for “free service or item.”

Additional information:

• Hedonist: A person who believes in pleasure as the most important goal of life.
• Stoic: A person who controls emotions and accepts pain or hardship calmly.

Last verified on 05-06-2026

Explanation

• Acquaintance means واقف کار
• Familiarity means واقفیت

Last verified on 10-02-2026