Question

20) Consider the two beakers laa Beaker B contains made of la known with certainty t w A) Beakers A and B contain an equal volume of woms B) Beakers and contain samples with the same density C) Beakers A and B contain an equal number of atoms D) Beakers A and B contain equal masses of atoms E) None of these are correct. 21 21) Which statement correctly de atement correctly describes what is happening in the reaction shown below 2Mg(s) + S260) - MgS(3) A) Mg is oxidized. B) Mg is the oxidizing agent. C) S2 loses electrons. D) MgS gains electrons. E) MgS is the reducing agent. 22) ZZ) The fluoride rinse in dental offices usually contains sodium fluoride, Sodium fluoride can be prepared from the reaction between sodium metal and fluorine gas. Which of the following properly represents the balanced chemical equation for this reaction? A) 2Na(s) + F268) - 2Na2F(3) B) Na(s) + F(g) - NaF(s) C) 7Na(s) +F) - Na7F(5) D) Na(s) + F2(8) - NaF2(5) E) 2Na(s) + F2(8) - 2NaF(3) 23) A given mass of oxygen at room temperature occupies a volume of 500.0 mL at 1.50 atm pressure. What pressure must be applied to compress the gas to a volume of only 150.0 mL? A) 150 atm B) 0.500 atm C) 1.50 atm D) 500 atm E) 5.00 atm

Answer 1

1 mole of any substance occupies =22.4L of Volume . . i mole Fe and 1 mole lead occupies Same voluwe I mole of substants = 6.023x102 atoms/moleculeslion. 1. I mole fe = 1 mole lead = 6.023x102?atomi. Aand c options are relavant. A and c are correct. amg (5) + (9-32M95 (1) mg solid elemetal form so oxidation number o n oridation number - 0 . "ngth igar A ng mga aidation - 5 - 5² reduction - Answer Mg is oridized, .. ng is reducing agent . I 'A' a gains the elections. } is oni dising agent. +2