Chemistry Answers

The neutralization reaction between hydrochloric acid (HCI) and calcium hydroxide [Ca(OH) 2 ] produces calcium chloride (CaCl_{2}) and water.

2HCl(aq) + Ca(OH)₂(s) → 2H₂O(l) + CaCl₂(aq)

If 0.75 grams of Ca(OH) 2 is used in the reaction, determine the following:

a.) number of moles of HCI(MM = 36.46 g/mol) needed to completely react with Ca(OH) 2 . The molar mass of Ca(OH) 2 is 74.10 g/mol.

b.) mass of CaCl₂ (MM 110.98 g/mol) formed in the reaction.

If 10.0 liters of oxygen at STP are heated to 512 °C, what will be the new volume of gas if the pressure is also increased to 1520.0 mm of mercury? *

how many grams of lactose must be added to 655 grams of water in order to prepare a solution with a percent mass concentration of 10%?

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?

2.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?

3.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?

4.How many grams of Lactic acid (C6H10O5) should be dissolved in 650g of cyclohexane (C6H12) to raise the boiling point to 84.910C? The normal boiling point of cyclohexane is 810C and its molal boiling point is 2.75 0C/m.

5.The osmotic pressure of 250mL of an aqueous solution containing 0.150g of the enzyme lysozyme is found to be 0.0013atm at 24.850 Calculate the molar mass of lysozyme.

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:

a. Mole Fraction of H2O2

b. Molarity

An 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:

a. Volume percent

b. Mass percent

c. Mass/volume percent

d. Mole fraction of Ethanol

e. Molarity

f. Molality

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)}

1. 2.5 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).

The recommended single dose for acetaminophen is 10.0

to 15.0 mg/kg

of body weight for adults. Using this guideline, calculate the maximum single dosage for a person who weighs 131 lb

.

mercury has a density of 13.6 g/mL. How many milliliters of mercury have a mass of 0.35kg?

Black iron oxide is an ore containing iron and oxygen that occurs in magnetite. A 2.4480 g sample of the ore is found to contain 1.7714g of iron. Calculate the empirical formula of black iron oxide.​