General Chemistry Answers

what is the resistance of a 30 m silver wire with a 2 mm diameter

Using the solubility curve answer the following question:

1. Which substance in the most soluble? ________________________________

2. Which substances increase its solubility through decrease in temperature? ______________

3. Which substance is least affected by an increase in temperature? ___________________

4. What is the solubility of KNO3, KCl, and Pb(NO3) at 40oC

_________________ _____________________ ______________________

A mixture of unknown salts containing a sulfate salt has been weighed to be 1.50 g. After dissolving the solution in 500 mL of water, heating it, and adding hot barium chloride (40.0 mL, 0.500 M); the precipitate has been collected after succeeding digestion, and the mass was found to be 0.325 g. What is the percentage (by mass) of sulfur in the mixture? 

Determine the spontaneity of the dissociation of ammonium nitrate the compound used in cold packs interpret the values obtained from the calculations

A mixture of unknown salts containing a sulfate salt has been weighed to be 1.50 g. After dissolving the solution in 500 mL of water, heating it, and adding hot barium chloride (40.0 mL, 0.500 M); the precipitate has been collected after succeeding digestion, and the mass was found to be 0.325 g. What is the percentage (by mass) of sulfur in the mixture? 

Calculate the mole fraction of a solution containing 2.6 grams of sodium sulfate in 20 grams of water

an unknown substance with a mass of 100 grams absorbs 1000 J while undergoing a temperature increase of 15 C. What is the specific heat of the substance 

1.Calculate the pH of a base buffer solution composed of 0.20 M NH₃ and 0.15 M NH₄Cl after the addition of 0.10 M HCl. The K_b of NH₃ at 25^oC is 1.80 × 10^-5.

2.What is the pOH of a buffer solution that is 0.150 M chloroacetic acid and 0.250 M sodium chloroacetate, after the addition of 0.100 M HNO₃? The value of K_a for chloroacetic acid is 1.3 x 10^-3.

In a certain reaction, 1.5g of ammonia was given and 2.75g of oxygen, how much NO is produced? (in mass and mole)

4NH3 + 502 --> 4NO + 6H20

When a research balloon is released at sea level, where the temperature is 14.8°C

14.8°C and the atmospheric pressure is 1.01×10

5

 Pa

1.01×105 Pa, the helium in it has a volume of 12.9 m

3

12.9 m3. The balloon reaches an altitude of 32 km

32 km, where the temperature is −44.1°C

−44.1°C and the pressure is 867 Pa

867 Pa. What is the volume of the helium at this altitude?