Chemistry Answers

“Substance E is composed of clear, red crystals. When the red crystals are heated, they crackle and change into a blue liquid, which cools to form a blue solid. Heating also produces vapour of substance X, which condenses to form a liquid that is a non-conductor of electricity. The colourless liquid of substance X is cooled until it forms a white solid. The solid of substance X does not conduct electricity. The red crystals of substance E are found to be quite soluble in water, but they do not dissolve in kerosene. Neither the red crystals nor the blue solid conducts electricity, although the red aqueous solution of substance E is a good conductor.”

What volume of hydrogen gas at STP is produced as sulfuric acid acts on 24 g of

calcium?

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

How many grams of the two products are formed if 10.0 moles of H2S04 is reacted with enough calcium phosphate [Ca₃(P0₄₎₂]?

Sulfuric acid (H₂S0₄₎ is used in the production of phosphate fertilizers.The reaction involved is

A Laboratory assistant prepares 5 litres of 0.1N hydrochloric acid stock solution using commercial HCl available in laboratory which has percentage purity of 35% (w/w) and specific gravity of 1.18 g/ml. Then he fills five 100ml standard flasks with 50.0ml of 0.1N HCl solution and dilutes it with distilled water upto the mark. Then he takes 10ml of diluted HCl solution from each flask into a conical flask, mixes it and adds 50ml of 0.025M Sodium hydroxide solution to it. Finally, he adds few drops of phenolphthalein to the resulting solution in the conical flask.

What was the concentration of HCl solution prepared in 100ml standard flasks?

What do you think will be the colour of the resulting solution after addition of indicator?

Calculate the pH of the resulting solution.

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? 

Maintaining constant pressure, the volume of a gas is increased from 18.0 L to 32.0 L by heating it. If the original temperature was 18.0°C, what is the new temperature in degrees Kelvin? Reminder, convert your temperature to Kelvin before you begin the problem.

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