General Chemistry Answers

1.25 The volume of solution was changed to 500mL by dissolving 2mL H2SO4 of relative importance in water. Determine the concentration of acid solution in mgL^-1 units.

How many grams of CuO aree needed to make 1500 mL of N2 at STP

Hydrogen sulfide gas is combusted with oxygen gas to produce sulfur dioxide gas and water vapour. If there is 48.4 L of oxygen available, what volume of hydrogen sulfide gas may be combusted if the pressure is held constant at 105 kPa and the temperature is held constant at 190°C?

Butane gas is combusted to produce carbon dioxide and water vapour. If 5.50 mol of butane are reacted, how many moles of water vapour are produced?

Ammonia is produced from its elements in a formation reaction. If 8.90 × 10²⁴ molecules of ammonia are produced, how many molecules of hydrogen were used?

Following the neutralization of a solution of dilute potassium hydroxide (KOH(aq)) with a solution of 0.50 mol/L hydrochloric acid (HCl(aq)), given :

Before neutralization

KOH(aq) with volume of 100 ml and temperature of 22 °C

HCl(aq) 0.50 mol/L and with volume of 50ml and temperature of 22.2°C

After neutralization

Mixture is now 150 ml as volume and 24.5 °C as temperature.

What is the value of the molar heat (ΔH) of neutralization of hydrochloric acid?

1.     A sample of chloroform is found to contain 12.0 g of carbon, 106.4 g of chlorine and 1.01 g of hydrogen. If a second sample of chloroform is found to contain30.0 g of carbon, how many grams of chlorine and grams of hydrogen does it contain?

What is the osmotic pressure of an aqueous solution containing in mol 500 cm3 dissolved 0.2 mol of potassium chloride (completely dissociated) and 2 g of glucose at 37 ° C?

1.      

2.     Freon-12 which has the formula CCl₂F₂ is used as a refrigerant in air conditioners and as a propellant in aerosol cans. Given a 5.56 mg sample of Freon-12:

a.      Calculate the number of molecules of Freon -12 in that sample

b.     How many mg of chlorine are in the sample?

 A 25 cm³ sample of hydrochloric acid is sucked into a pipette and transferred into a 250 cm³ volumetric flask. The solution is made up to the mark.

 25 cm³ of the diluted acid is transferred into a conical flask using a pipette.

 A burette is used to neutralise the acid with 0.100 mol dm^-3 sodium hydroxide.

Hydrochloric acid reacts with sodium hydroxide according to the equation:

HCl_(aq) + NaOH_(aq)  NaCl_(aq) + H₂O_(l)

 The average titre of the sodium hydroxide solution was 30.00 cm³. Calculate the number of moles in the average titre