Lec-31-Chap5-3

# Lec-31-Chap5-3 - Solution Concentration Relative amounts of...

This preview shows pages 1–4. Sign up to view the full content.

Relative amounts of solute and solvent. There are several concentration units. Most important to chemists: Molarity Molarity ± solute solute – substance dissolved. ± solvent solvent – substance doing the dissolving. Solution Concentration Molarity = moles solute liters of solution = V of solution not not solvent. mol L The brackets [ ] represent “molarity of ” The brackets [ ] represent “molarity of ” • Shorthand: [NaOH] =1.00 M Molarity

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Molarity Calculate the molarity of sodium sulfate in a solution that contains 36.0 g of Na 2 SO 4 in 750.0 mL of solution. n Na2SO4 = 36.0 g 142.0 g/mol = 0.2534 mol [Na 2 SO 4 ] = 0.2534 mol 0.7500 L [Na 2 SO 4 ] = 0.338 mol/L = 0.338 M Unit change! (mL to L) Molarity (a) A l (NO 3 ) 3 FM = 26.98 + 3(14.00) + 9(16.00) [ A l (NO 3 ) 3 ] = 2.991 x 10 -2 mol / 0.250 L = 0.120 M 6.37 g of A l (NO 3 ) 3 are dissolved to make a 250. mL aqueous solution. Calculate (a) [A l (NO 3 ) 3 ] (b) [A l 3+ ] and [NO 3 - ]. n Al(NO3)3 = = 2.991 x 10 -2 mol 6.37 g 213.0 g/mol g mol = 213.0
Molarity 6.37 g of A l (NO 3 ) 3 in a 250. mL aqueous solution. Calculate (a) the molarity of the A l (NO 3 ) 3 , (b) the molar concentration of A l 3+ and NO 3 - ions in solution. (b) Molarity of A l 3+ , NO 3 - ? A l (NO 3 ) 3 (aq) A l 3+ (aq) + 3 3 NO 3 - (aq) 1 A l (NO 3 ) 3 1 A l 3+ 1 A l (NO 3 ) 3 3 NO 3 - [A l 3+ ] = 0.120 M A l (NO 3 ) 3 = 0.120 M A l 3+ 1 A l 3+ 1 A l (NO 3 ) 3 [NO 3 - ] = 0.120 M A l (NO 3 ) 3 = 0.360 M NO 3 - 3 NO 3 -

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 11/14/2010 for the course CHE 131 taught by Professor Kerber during the Spring '08 term at SUNY Stony Brook.

### Page1 / 9

Lec-31-Chap5-3 - Solution Concentration Relative amounts of...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online