Molarity Problems Molarity molL Molarity moles of solute

Molarity Problems Molarity = mol/L Molarity = moles of solute / Liters of solution

Concentration ~How much solute is present in a solution compared to the solvent. n Molarity (M)- moles of solute per liter of solution. M = mol/L n 2. 1 M Ag. NO 3 means 2. 1 mol of Ag. NO 3 for every one liter of solution n

Other measures of concentration Name Abbrev. What it is molality m mol solute/kg solvent parts per million ppm g solute/g solvent x 106 parts per billion ppb g solute/g solvent x 109 mole fraction x mol solute/mol solution percent by mass % g solute/g solution x 100 percent by volume % m. L solute/m. L solvent x 100

Molarity problems How many moles of HCl are in 125 m. L of 2. 5 M HCl? . 125 L of soln 2. 5 mol HCl =. 31 mol HCl n 1 L of soln.

Here we go n What concentration solution would be prepared if 39 g of Ba(OH)2 were mixed in a 450 m. L solution? 39 g Ba(OH)2 1 mol Ba(OH)2 =. 2276 mol Ba(OH)2 171. 316 g Ba(OH)2 M = mol/L . 2276 mol Ba(OH)2. 45 L of solution =. 51 M Ba(OH)2

More For a lab in this chapter, I need to make. 60 L of 3. 0 M Na. OH, what mass of Na. OH did I need? n. 6 L x 3. 0 M Na. OH = 1. 8 mol Na. OH n 1. 8 mol Na. OH x 39. 998 g/mol n = 72 g Na. OH n

More molarity problems How many moles of HCl are in 525 m. L of 3. 5 M HCl? . 525 L of soln 3. 5 mol HCl = 1. 8 mol HCl n 1 L of soln.

Still going n What concentration solution would be prepared if 48 g of Ca(OH)2 were mixed in a 450 m. L solution? 48 g Ba(OH)2 1 mol Ba(OH)2 =. 65 mol Ba(OH)2 74. 096 g Ba(OH)2 M = mol/L . 65 mol Ba(OH)2. 45 L of solution =1. 4 M Ba(OH)2

For a lab in this chapter, I need to make. 75 L of 3. 0 M Na. OH, what mass of Na. OH did I need? n. 75 L x 3. 0 M Na. OH = 2. 25 mol Na. OH n 2. 25 mol Na. OH x 39. 998 g/mol n = 90. g Na. OH n

Molarity Problems n A 0. 24 M solution of Na 2 SO 4 contains 0. 36 moles of Na 2 SO 4. How many liters were required to make this solution? 0. 36 mol Na 2 SO 4 = 1. 5 L Na 2 SO 4 1 L soln 0. 24 mol

Getting tougher Ba. Cl 2 2 Ag. Cl + Ba(NO 3)2 n Balance the equation. If 1. 2 L of. 50 M Ag. NO 3 is reacted completely, what molarity solution of Ba(NO 3)2 will be created if the volume increased to 1. 5 L? n 2 Ag. NO 3 + 1. 2 L x. 5 M Ag. NO 3 =. 6 mol Ag. NO 3 1 mol Ba(NO 3)2 =. 3 mol Ba(NO 3)2 2 mol Ag NO 3 1. 5 L =. 20 M Ba(NO 3)2

Last one Zn H 2 + Zn(NO 3)2 n If you have. 65 L of 1. 2 M HNO 3 and you react it completely what volume of H 2 gas will you produce at STP? n 2 HNO 3 + 1. 2 M HNO 3 x. 65 L =. 78 mol HNO 3. 39 mol H 2 1 mol H 2 2 mol HNO 3 22. 4 L at STP 1 mol H 2 =. 39 mol H 2 = 8. 7 L at STP

Homework Problem HNO 3 + Zn H 2 + Zn(NO 3)2 n If you have. 45 L of 2. 1 M HNO 3 and you react it completely what volume of H 2 gas will you produce at STP? n Solve for moles of H 2, then use Avogadro’s law to get a volume at STP. n