Heat of Solution Practice

Heat of Solution Practice

What is the heat of solution if a 50 g water sample goes from 22 C to 19 C when 88 g HCl is dissolved?

What is the heat of solution if a 215 g sample of water goes from 19.8 C to 16.9 C when 331 g of H3PO4 is dissolved?

What is the heat of solution if a 512 g sample of water goes from 19.1 C to 23.7 C when 476 g of MgCl2 is dissolved?

How much 2 M Fe(OH)3 is needed to react with 221 mL of 3 M H2SO4?

How much 5 M NaOH is needed to react with 1,201 mL of 3 M H3PO4?

What is the heat of solution if a 50 g water sample goes from 22 C to 19 C when 88 g HCl is dissolved?

(88 g HCl)(1 mol HCl/36.46 g HCl) = 2.41 mol HCl

(4.18J/1g H2O 1C)(50 g H2O)(-3 C) = -627J or -.627 kJ

Heat of Solution = kJ/mol

+.627 kJ/2.41 mol +.26 kJ/mol

What is the heat of solution if a 215 g sample of water goes from 19.8 C to 16.9 C when 331 g of H3PO4 is dissolved?

(331 g H3PO4)(1 mol H3PO4 /98.00 g H3PO4) = 3.38 mol H3PO4

(4.18J/1g H2O 1C)(215 g H2O)(-2.9 C) = -2606.23 or -2.60623 kJ

Heat of Solution = kJ/mol

+2.60623 kJ/3.38 mol +.77 kJ/mol

What is the heat of solution if a 512 g sample of water goes from 19.1 C to 23.7 C when 476 g of MgCl2 is dissolved?

(476 g H3PO4)(1 mol MgCl2 /95.21 g MgCl2) = 5.00 mol MgCl2

(4.18J/1g H2O 1C)(512 g H2O)(4.6 C) = 9844.74 or 9.84474 kJ

Heat of Solution = kJ/mol

9.84474 kJ/5 mol 1.97 kJ/mol

How much 2 M Fe(OH)3 is needed to react with 221 mL of 3 M H2SO4?

2 Fe(OH)3 + 3 H2SO4-> Fe2(SO4)3 + 6H2O

(3 mol H2SO4/1 L H2SO4)(1 L/1000 mL)(221 mL H2SO4)(2 mol Fe(OH)3 /3 mol H2SO4)(1 L Fe(OH)3 /2 mol Fe(OH)3) = .221 L or 221 mL Fe(OH)3

How much 5 M NaOH is needed to react with 1,201 mL of 3 M H3PO4?

3NaOH + H3PO4-> Na3PO4+ 3H2O

(3 mol H3PO4/1 L H3PO4)(1,201 mL H3PO4)(1 L/1000 mL)(3 mol NaOH/1 mol H3PO4)(1 L NaOH/5 mol NaOH) = 2.16 L NaOH