General Chemistry Answers

1. Oxygen gas was collected over water in a gas collection tube.  What is the pressure of "wet" oxygen gas (this means dry oxygen gas and water vapour) if 0.8 mol of dry oxygen gas, with a partial pressure of 101.3 kPa, was collected over water at a temperature of 15.0°C?
2. Solid magnesium was added to a gas collection tube containing hydrochloric acid and water. Gas was collected by displacing the water in the tube.  After the experiment, the total pressure in the tube was equalized with the atmospheric pressure, which was 114 kPa.  The temperature of the water was 35°C.  What was the partial pressure of the dry hydrogen gas?

How many grams of anhydrous remains when 40.0g of KAl(SO4)2 . 12H2O is heated until all water has been liberated?

Strontium-90 has a half life of 28.1 yrs. Starting with 3.20 mg of this isotope, how much would remain after 112.4 years?

1.The half-life of chromium-51 is 28 days. If the initial amount of chromium-51 is 133 mCi, how much chromium-51 is left in the body after 84 days?

1. The following reaction occurs at 25oC

                                H2(g) + I2(g) ↔ 2HI(g)

a)   Write the equilibrium expression for Kc

 b) Calculate Kc at 25 degrees C if the equilibrium concentrations are  [H2]=0.106 M,        

                  [I2]=0.022 M, and  [HI] = 1.29 M

While a sample of liquid is freezing its thermal energy increase or decrease?

Which of the following is true for a chemical reaction at equilibrium?

I. only the forward reaction stops

II. only the reverse reaction stops

III. both the forward and reverse reactions stop

IV. the rate constants for the forward and reverse reactions are equal

V. the rates of the forward and reverse reactions are equa

the temperature of a gas started at 312 with a yolume of 4.5 L increased to 372 with a new volume of 1.2 what would the new pressure be if the initial pressure was 1.1 atm

A student calculated the molarity of a solution prepared by dissolving 0.730 mol of table sugar (sucrose, C₁₂H₂₂O₁₁) in 1.8x10^3 mL of water as 4.06x10^-4 M C₁₂H₂₂O₁₁. 

how would you prepare 2.0L of a 1.0M hci solution from 12.0m stock solution of hci?