Question

1. Which statement is true? A) The process of diluting a solution in the laboratory is much like preparing juice from a canned concentrate of the juice. B) Molarity is defined as the moles of solute divided by the liters of solvent. C) N2O5 has 2.5 times as many nitrogen atoms as oxygen atoms D) The number of formula units in 2.0 moles of MgCl2 is 6.022 x 1023 2. A 6.25 g sample of magnetite (Fe3O4) contains 4.52 g of Fe. What are the percentages of iron and oxygen in magnetite? A) 28.6% Fe and 71.4% 0 B) 42.8% Fe and 57.2% 0 C) 72.3% Fe and 27.7% O D) 27.7% Fe and 72.3% O E) 57.2% Fe and 42.8% O 3. The formula for novocain, a local anesthetic, is C13H2N202. What is the molar mass of this compound? A) 43.03 g/mol B) 237.32 g/mol C) 2035.27 g/mol D) 38.00 g/mol E) 4.214 x 10-5 g/mol

Answer 1

Moleular amula of novocain C13H21N262 Gsam Atomi Tmasseo C12-9 H 9 N 49 of (12x12+ Molar mass C2M21 N202 21xl +14 X2 + 16x2) SC21 28 32 2319 mal Aws 2 3-329m

(magmekle) Fe3 04 Innene Spirel to (), 6-253 ala OA Mass of Fe304 pranent Amaut of Fe pronent 4-S29 Amont of onen prout C25-1 25 - F3_9 iton prant = _4.5 2 X00 6. 25 2 3./ 72-32 6.25 27 7 27 687 Ano Fe = F2-3

Stalennents B Molari y solute defmed prorent in volume of saluton in 1it poblem twa given volune f solut of mabo of an the no Ln He only. Thuo inoznect N205 has 2-S mes an mony ahoms. ap on OfN-0- .of Nthen 0. tfore Me ILhoo less no. Stalemah incosrest

Moles 0f Nac No of foormla uit Avogandas No No.af forma wit C02ax1 Sage 2 No. f fomula unt 22 6.022X2X10 12.04x 1023 20 x to24 Henca the 9hen stalemet s meosnect CET Tho Pocess laboratosy much ika pre parng juce a Camad Concantrak ef hesuee of dilhiy a solution th the r fam Cona Soln Diluted Soln Sovant D/luhon 0 ug her Concs Lower Conc A Coroect satemat