аЯрЁБс>ўџ 46ўџџџ3џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџьЅС` јПъbjbjЫsЫs .ЉЉQ˜џџџџџџЄzzzzzzzŽђђђ8*>$Ž“Жnn„„„„„„$IhБ†8z„„„„„8zz„„MТТТ„z„z„Т„ТТzzТ„b e|PЧђ„ˆТc0“Т7 ^7Т7zТP„„Т„„„„„88jX„„„“„„„„ŽŽŽd ђŽŽŽђŽŽŽzzzzzzџџџџ Concentration Review Worksheet 1) If I make a solution by adding 83 grams of sodium hydroxide to 750 mL of water… a) What is the molality of sodium hydroxide in this solution? b) What is the percent by mass of sodium hydroxide in this solution? c) What is the mole fraction of sodium hydroxide in this solution? 2) If I make a solution by adding water to 35 mL of methanol (CH3OH) until the final volume of the solution is 275 mL… a) What is the molarity of methanol in this solution? (The density of methanol is 0.792 g/mL) b) What is the percent by volume of methanol in this solution? Concentration Review Worksheet Answers 1) If I make a solution by adding 83 grams of sodium hydroxide to 750 mL of water… To solve problem 1, you need to have calculated for various parts that there are 2.08 moles of NaOH (which has a molar mass of 40 g/mol), that there are 750 grams of water (which has a density of 1 g/mL), and that there are 41.67 moles of water (which has a molar mass of 18 g/mol). a) What is the molality of sodium hydroxide in this solution? 2.77 m (2.08 mol / 0.75 kg water) b) What is the percent by mass of sodium hydroxide in this solution? 9.96% (found by finding 83 g / 833 g and multiplying by 100%) c) What is the mole fraction of sodium hydroxide in this solution? 0.0475 (found by finding 2.08 mol / 43.75 mol) 2) If I make a solution by adding water to 35 mL of methanol (CH3OH) until the final volume of the solution is 275 mL… When solving this problem, you’ll need to calculate that there are 27.72 grams of methanol (from the density), which is equal to 0.866 mol. a) What is the molarity of methanol in this solution? (The density of methanol is 0.792 g/mL) 3.15 M (0.866 mol/0.275 L) b) What is the percent by volume of methanol in this solution? 12.7% ( (35 mL/275 mL) X 100)     For chemistry help, visit  HYPERLINK "http://www.chemfiesta.com" www.chemfiesta.com Љ 2007 Cavalcade Publishing, All Rights Reserved Ž  ћ % j l “ щ   E f Б ю 7 > g Ќ ­ т pдю012PQRTUWXZ[]wxŸ ЁїюъхъсъсъсисгЫсгсгсЫгсЦсгсгсПсгЗЏЋЏЋЏЋЏЋЁ’Ё€’"jh‹h‹6CJUjh‹h‹6CJUh‹h‹6CJh$ 1jh$ 1Uh›ѕhПDё5 hПDёh›ѕ h›ѕH*h›ѕh›ѕ5 h›ѕ5h›ѕ5>*CJ$h›ѕ hПDёH*hПDёh*CJ$hПDё5>*CJ$- stВДЕЖЗИЙўџ     G H I J K L M їђхђмђђђђђђмђђђђђђмђђђђђђ„а`„аgdПDё „а„0§^„а`„0§gdПDёgdПDё$a$gdПDёQщ§§M N Х Ц % & ' ( ) * + , k “ ” ч ш   C g h њэњффњњњњњњњфмзЪЪЪзСзз„а`„аgd›ѕ „а„0§^„а`„0§gd›ѕgd›ѕ$a$gd›ѕ„а`„аgdПDё „а„0§^„а`„0§gdПDёgdПDёh i j Џ я № ё ђ 5 h i j k l у ф rsЙвя№ёђ1Qњњёњњњњёњњњњњфффњёёњњњњёл„а`„аgdПDё „а„0§^„а`„0§gd›ѕ„а`„аgd›ѕgd›ѕQSTVWYZ\]чшщъ§§§§§§§§ћ§§ђ„а`„аgdПDё ЁГДЕЖчщъѓфкгкЯЧh›ѕhПDё5h$ 1 h‹6CJh‹h‹6CJjh‹h‹6CJUh‹h‹0J6CJ,1hАа/ Ар=!А"А# $ %ААаАа абDаЩъyљКЮŒ‚ЊKЉ www.chemfiesta.comрЩъyљКЮŒ‚ЊKЉ 6http://www.chemfiesta.com/†œH@ёџH N ЋNormal CJOJQJ_HaJmH sH tH DA@ђџЁD Default Paragraph FontRi@ѓџГR  Table Normalі4ж l4жaі (k@єџС(No List(ўOђ( E Style14@4 ‹Header  ЦрР!4 @4 ‹Footer  ЦрР!6U@Ђ!6 ‹ Hyperlink >*B*phџъ џџџџ stВДЕЖЗИЙўџGHIJKLMNХЦ %&'()*+,k“”чшCghijЏя№ёђ5hijklуфrsЙвя№ёђ1QSTVWYZ\]чшы˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜0€€˜@0€€˜0€€˜0€€˜0€€˜@0€€˜@0€€˜0€€˜@0€€˜@0€€˜@0€€˜@0€€˜0€€˜@0€€˜@0€€˜@0€€˜@0€€˜0€€˜@0€€˜@0€€˜@0€€˜@0€€˜0€€˜0€€˜0€€˜@0€€˜@0€€˜0€€˜0€€˜@0€€˜@0€€˜@0€€˜@0€€˜0€€hЫ00аh‹00 hЫ00аh‹00 hЫ00аh‹00 hЫ00аh‹00 @0€€hЫ00 h‹00X  ———šЁъM h Qъ щ &ObšXџ„ 7@КТ8;QQSSTTVWYZ\]шы3333lPQQSSTTVWYZ\цыQQSSTTVWYZ\]шых E š %$ 1О"R