General Chemistry Answers

3.)calculate the molality of phosphoric acid, H3PO4, in a solution of 29.0g H3PO4 in 250.0g H2O. (atomic mass :H=1.008g/mol:P=30.97g/mol:O=16.00g/mol:Ans.m=1.18mol solute /kg solvent)

4.)Refer to the data given in problem #3, calculate the mole fraction of H3PO4 and H20. (Ans. X H3PO4 =0.979:XH20=0.0209

5.)An aqueous solution has 0.0400g of NaCl (salute) in 2.00kg H2O(solvent). What is the concentration of the solution in parts per million

6.)calculate the volume, in mL, of 1.72M HCl solution that will react with 2.67 mol of CaCO3? (Ans. 3.10x103mL)

__HCl+__CaCl2+__H2O+__CO2

7.)If 0.650% solution of Na2CO3 will be used to precipitate Ca+2 from solution, determine the amount of solution, in grams, needed to precipitate 5.00x102mL of 0.01120M Ca+? (Atomic mass :Na 22.99g/mol:C=12.01g/mol:O=16.00g/mol:Ca=40.08g/mol:Ans.91.3g

___Na2CO3(aq)+__Ca+2(aq)___CaCO3(s)+___Na+(aq)

A storage tank contains 2 moles of Ar, 3 moles of O2, and 5 moles

of N2 at a total pressure of 1000 torr. Calculate partial pressure of

each gas

Calculate the molality of a 0.410 molar aqueous solution whose density is 1.15 g/mL.

A storage tank contains 2 moles of Ar, 3 moles of O2, and 5 moles

of N2 at a total pressure of 1000 torr. Calculate partial pressure of

each gas.

What is the entropy change of the reaction below at 298 K and 1 atm pressure? N2(g) + 3H2(g) → 2NH3(g) S 0 298 (J/mol•K) 191.5 130.6 192.3

(a) –198.7 J/K

(c) –129.7 J/K

(b) 76.32 J/K

(d) 303.2 J/K

Write the balanced COMPLETE ionic equation for the reaction when FeBr₃ and (NH₄)₂S are mixed in aqueous solution. If no reaction occurs, simply write only NR.

You have 2.2 mol Xe and 4.0 mol F₂, but when you carry out the reaction you end up with only 0.25 mol XeF₄. What is the percent yield of this experiment?

Xe(g) + 2 F₂ (g) → XeF₄ (g)

A 500cm3 of solution is prepared by dissolving 0.25g of CaCo3 in excess HCl.Ca2+ ions concentration in the solution in ppm?

What is the total number of moles of ions present in a solution after mixing 125cm3 of 0.2M NaOH and 125cm3 of 1M H2SO4

An aqueous solution K2SO4.Cr(SO4)3.12H2O contains 2.08gdm-3 of Cr3+ ions .what is the SO4^2- concentration in moldm-3 in this solution