devrahycinth

Thermite is a mixture of iron(III) oxide and aluminum powders that was once used to weld railroad tracks. It undergoes a spectacular reaction to yield solid aluminum oxide and molten iron. How many moles of iron(III) oxide are needed to form 3.603103 mol of iron? 

What is the percent yield of a reaction that produces 12.5 g of the freon CF2Cl2 from 32.9g of CCl4 anf  excess HF?

At what temperature must an 850cc of gas initially at 27*c be heated to increase the volume by 50%

At 50°C, the lion-product constant for H2O has the value Kw = 5.48×10^-14. (a) what is the pH of pure water at 50°C

A heat engine has a hot reservoir at 214C and a cool reservoir at 68C. What is the maximum efficiency of this engine?

A gas at 413K is cooled to 385K. As this happens the volume of the gas goes from . If the initial pressure is , what is the final pressure?

A sample of water 2.35kg is heated from 13C to 94C. What is the change in entropy of the sample?

 

Calculate the freezing point of a solution of 3.46 g of a compound, X, in 160 g of
benzene. When a separate sample of X was vaporised, its density was found to be
3.27 g/L at 116°C and 773 torr. The freezing point of pure benzene is 5.45°C, and
Kf is 5.12°C kg/mol.

What is 11/12 + 2/5 in the simplest form?

Determine the mass in grams of 0.692 mol C8H18

Pure benzene freezes at 5.45°C. A solution containing 7.24 g of C2Cl4H4 in 115.3 g of benzene was observed to freeze at 3.55°C. From these data, calculate the molal freezing point depression constant of benzene.

Which two words have opposite meanings ?

A. Swirled & rolled

B. Blooms & Flowers

C. Dreary & Bright

D. Wondrous & Astonishing