A sealed glass jar has a small amount of water on the bottom. The rest of the volume in the jar is taken up by helium gas at a partial pressure of 526 mmHg, and water vapor. If the total pressure inside the jar is 760. mmHg, what is the temperature of the water?

An aqueous solution of sodium chloride,NaCl , is made by dissolving 1.01 grams of sodium chloride in sufficient water in a 50.0 mL volumetric flask, and then adding enough water to fill the flask to the mark. What is the weight/volume percentage of sodium chloride in the solution? Weight/volume percentage =           %

A geochemist measures the concentration of salt dissolved in Lake Parsons and finds a concentration of 11.10 g.L-¹. The geochemist also measures the concentration of salt in several nearby non-isolated lakes, and finds an average concentration of 4.30 g⋅L¯¹. Assuming the salt concentration in Lake Parsons before it became isolated was equal to the average salt concentration in nearby non-isolated lakes, calculate the percentage of Lake Parsons which has evaporated since it became isolated. Be sure your answer has the correct number of significant digits.

barrels of toluene are being stored on the moon for use in onsite manufacturing. If each barrel contains 42 gallons, how many moles are in each container? The specific gravity of toluene is 0.867 and its molecular formula is C7H8. you may assume the molecular weights of carbon and hydrogen are 12 and 1 g/mol, respectively.

Expressing amounts of energy in different energy units is necessary to solve many chemistry problems. For practice, complete the following table. The Joule (J) is the SI unit of energy. 1 calorie (cal) = 4.184 J 1 kWh = 3.600 x 106 J J 202 kWh 199 kcal 226

(Incorrect) An impure sample of hydrocarbon having a total mass of 41.0 g undergoes combustion analysis to generate 82.6 g CO₂(g) and 16.9 g H₂O(g). Assuming that the impurities do not contain carbon or hydrogen, what percentage of the initial sample is the pure hydrocarbon? Provide the numerical value of your response in decimal notation rounded to 3 significant figures. You answered: 4.58 The correct answer is: 59.5%

About two centuries ago, Benjamin Franklin showed that 1teaspoon of oil would cover about 0.5 acre of still water. If you know that 1.0 x 104 m2= 2.47 acres and that there is approximately 5 cm3 in a teaspoon, what is the thickness of the 0.5-acre layer of oil? How might this thickness be related to the sizes of molecules?

9. What might the reaction coordinate diagram look like for the following reaction? ii - Free energy Ryn progress

Balance each of the following chemical equations. Give your answer as coefficients separated by commas. Na2S(aq)+Cu(NO3)2(aq)→NaNO3(aq)+CuS(s) Express your answers as integers separated by commas.