Chemistry Answers

1. You add 1 kg of ethylene glycol (C₂H₆O₂) antifreeze to 4500g of H₂O in your car’s radiator. What would be the freezing point of the solution?

1. A solution prepared by adding 10g of an unknown non-volatile, non-electrolyte solute to 150 g of water. The Boiling point of the solution is elevated by 0.433 ⁰C above the normal boiling point of the solvent. What is the molar mass of the unknown substance?

1. What is the vapor pressure of the pure solvent if the vapor pressure of a solution of 15g sucrose (C₁₂H₂₂O₁₁) in 100g of ethanol (C₂H₅OH) is 58 mmHg?

1.  mL of nitric acid, HNO₃, are required to react with 50 mL of a 1.25 M Barium hydroxide, Ba(OH)₂ solution:

2 HNO_3 (aq)           +      Ba(OH)_{2 (aq)} -->    2 H₂O _(aq)    +      Ba(NO₃)_{2 (aq)}

Determine the concentration (Molarity) of the nitric acid solution (HNO₃).

1. How many mL of 0.250 M barium nitrate are required to precipitate as barium sulfate all the sulfate ions from 50 mL of 0.350 M aluminum sulfate?

3 Ba(NO₃)_{2 (aq)}           +       Al₂(SO₄)_3 (aq)     -->   3 BaSO_{4 (s)}  + 2 Al(NO₃)_{3 (aq)}

Constraints on the number of independently moving particles; i.e., on whether the particles must move as an aggregate or can move separately.How thermodynamic properties Entropy, would now respond to this constraints

Hydrogen peroxide (H₂O₂) is a powerful oxidizing agent used in concentrated solution in rocket fuels and in diluted solutions is hair bleach. An Aqueous solution of 25% (m/m) has a density of 1.05 g/ml. Calculate the concentration in terms of:

n ethanol solution is prepared by dissolving 15 mL of ethanol (C₂H₅OH) (density: 0.850 g/ml) in a sufficient volume of water to produce 120 mL of solution with a density of 0.980 g/mL. What is the concentration of ethanol in this solution expressed as:

constraints in a molecular system

1. Constraints on the number of independently moving particles; i.e., on whether the particles must move as an aggregate or can move separately.

2. Constraints on the direction of motion.

3. Constraints on the volume in which the motion is executed

How thermodynamic properties, in particular Entropy, would now respond to these constraints.

Phosphoric acid (H_{3}*P * O_{4}) can be prepared from phosphorus triiodide (P*l_{3}) according to the reaction:

PI 3 (s)+H 2 O(l) H 3 PO 4 (aq)+HI(g)

Balance the equation. If 150 grams of Pl_3 ( MM=411.7 g/mol) is added to 250 milliliters og H 2 O(MM=18.01 g / mol , rho=1.00 g mL ) identify the limiting and excess reagents. How many grams of H3PO4 (MM=97.99 g / mol ) will be theoretically produced?