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A perfect gas has a value of R= 58.8 ft-lb/lb-R and k= 1.26. IF 20 Btu are added to 5 lb of this gas at constant volume when the initial temperature is 90°F, what is the change in entropy?
A heat engine absorb 750J of heat from a hot performs 265J of work calculate the efficiency of the heat engine.
A chunk of plastic is weighed on a scale and has a mass of 68.29 g. Next, the chunk is submerged in a graduated cylinder with an initial volume of water of 100.0 mL. After the plastic is added, the new volume in the cylinder is 129.5 mL. Find the density of the plastic in g/cm3.
Solve for what is asked in the following problem, show your complete solution
Student A investigated the rate of reaction between calcium carbonate (marble chips) and hydrochloric acid. The student collected 10.0 cm3 of gas produced after 15 seconds.Student B investigated the rate of reaction between magnesium and hydrochloric acid. The student collected 19.5 cm3 of gas produced after 10 seconds.Which student’s investigation had a faster rate of reaction?
Given the balanced equation below for the highly exothermic reaction of aluminum
with oxygen to form aluminum oxide:
4Al(s) + 3O2(g) 2Al2O3(s) ∆H = - 1,670 kJ
a. What is the value of ∆H when 2 moles of aluminum react?
b. What is the value of ∆H when 10.8 g of aluminum reacts?
c. A certain reaction releases 6,881 kJ of heat. What mass of aluminum oxide was
produced in the reaction?
Given the formula for change in internal energy, U = Q + W, calculate work for a
system that absorbs 350 kJ of heat and for which U = 150 kJ. Is the work done on
the system or by the system? Does the system expand or contract?
A sample biogas contains 10.75 mol ethane, 6.35 mol pentane and 2.89 mol propane. If the total pressure I 2. 46 atm, What are the partial pressures of the gases?
1. What is the boiling point and freezing point of a solution containing 6 g of
glycerol (C3H8O3) in 25 g of water?
2. What is the molecular mass of a solute in a solution containing 3.8 g of
nonelectrolyte in 420 g of water which freezes at -23 oC?
Identify what colligative property is applied or observed in the following. Explain
your answer.
1. Salt is mixed with ice in ice cream making.
2. Salt and sugar are used in food preservation.
3. Coolant is added to car radiators.
4. Pressure cooker.
5. Pruned or wrinkled fingers.
Solve for what is being asked.
What is the molar mass of the solute in a solution made by dissolving 34.41
g of an unknown nonelectrolyte compound in 280.0 g benzene. The boiling point of
the solution is 93.2 °C. Benzene has a boiling point of 80.1 °C and molal boiling-
point elevation constant of 2.53 °C/m.
