General Chemistry Answers

the density of octane, a component of gasoline, is 0.702 g/ml. What is the mass, in kg, of 875 mL of octane?

A group of students collected 125 empty aluminum cans to take to the recycling center. If 21 cans make 1.0 pound of aluminum, how many liters of aluminum (D=2.70g/cm³) are obtained from the cans?

The density of octane, a component of gasoline, is 0.702g/ml. What is the mass, in kg, of 875 mL of octane?

Calculate the standard enthalpy change for the reaction 2𝐴𝑙(𝑠) + 𝐹𝑒2𝑂3(𝑠) → 2𝐹𝑒(𝑠) + 𝐴𝑙2𝑂3(𝑠)

given that

2𝐴𝑙(𝑠)+3𝑂 (𝑔)→𝐴𝑙 𝑂 (𝑠) ∆𝐻° =−1669.8 𝑘𝐽 22 23 𝑟𝑥𝑛 𝑚𝑜𝑙

2𝐹𝑒(𝑠)+3𝑂 (𝑔)→𝐹𝑒 𝑂 (𝑠) ∆𝐻° =−822.2 𝑘𝐽 22 23 𝑟𝑥𝑛 𝑚𝑜𝑙

A sheet of gold weighing 10.0 g and at a temperature of 18.0°C is placed flat on a sheet of iron weighing 20.0 g and at a temperature of 55.6°C. What is the final temperature of the combined metals? Assume that no heat is lost to the surroundings. (Hint: The heat gained by the gold must be equal to the heat lost by the iron. The

specific heats of the gold and iron are 0.129 and 0.444 𝐽 , respectively

A piece of silver of mass 362 g has a heat capacity of 85.7 J/°C. What is the specific heat of silver?

The first step in the industrial recovery of zinc from the zinc sulfide ore is roasting, that is, the conversion of ZnS to ZnO by heating:

2𝑍𝑛𝑆(𝑠) + 3𝑂2(𝑔) → 2𝑍𝑛𝑂(𝑠) + 2𝑆𝑂2(𝑔) ∆𝐻 = −879 𝑘𝐽 𝑚𝑜𝑙

Calculate the heat evolved (in kJ) per gram of ZnS roasted

 The first step in the industrial recovery of zinc from the zinc sulfide ore is roasting, that is, the conversion of ZnS to ZnO by heating:

2𝑍𝑛𝑆(𝑠) + 3𝑂2(𝑔) → 2𝑍𝑛𝑂(𝑠) + 2𝑆𝑂2(𝑔) ∆𝐻 = −879 𝑘𝐽 𝑚𝑜𝑙