Stoichiometry Stoichiometry MCQS#Physical Changes66Choose the best answerWhich change can be reversed without forming a new substance?ABurning paperBMelting iceCRusting ironDCooking an egg Like 0 Discuss 0Share
StoichiometryMole–Volume Stoichiometry67Choose the best answerSodium reacts with water: 2Na + 2H₂O → 2NaOH + H₂ What volume of H₂ at STP is produced by 20 mol Na?A762 LB112 LC448 LD224 L Like 0 Discuss 0Share
StoichiometryMole–Volume Stoichiometry68Choose the best answer0.25 mol N₂ reacts with excess H₂: N₂ + 3H₂ → 2NH₃ The volumes of H₂ consumed and NH₃ produced at STP (273 K and 1 atm) are respectively:A16.8 L and 11.2 LB33.6 L and 11.2 LC11.2 L and 2.8 LD22.4 L and 5.6 L Like 0 Discuss 0Share
Stoichiometry Stoichiometry MCQS#Avogadro's Number69Choose the best answerIf Avogadro’s number changed from 6.022 × 10²³ mol⁻¹ to 6.022 × 10²⁰ mol⁻¹, which quantity would change?AThe definition of mass in units of grams.BThe mass of one mole of carbon.CThe ratio of chemical species in a balanced equation.DThe ratio of elements in a compound. Like 0 Discuss 0Share
Stoichiometry Stoichiometry MCQS#Chemical Changes70Choose the best answerWhich observation is the strongest evidence that a chemical reaction has occurred?AA substance changes its shapeBA new gas is formed during the reactionCA solid is broken into smaller piecesDSugar dissolves in water Like 0 Discuss 0Share