Questions from General Chemistry

Q: A 25.0-g sample of pure iron at 85

A 25.0-g sample of pure iron at 85 °C is dropped into 75 g of water at 20. °C. What is the final temperature of the water–iron mixture?

Q: For each of the substances listed in Table 10.1,

For each of the substances listed in Table 10.1, calculate the quantity of heat required to heat 150. g of the substance by 11.2 °C.

Q: The overall reaction in commercial heat packs can be represented as

The overall reaction in commercial heat packs can be represented as 4Fe(s) + 3O2(g) 2Fe2O3(s) ∆H = -1652 kJ a. How much heat is released when 4.00 moles of iron is reacted with ex...

Q: Consider the following equations: 3A + 6B 3D ∆H

Consider the following equations: 3A + 6B 3D ∆H = -403 kJ/mol E + 2F A ∆H = -105.2 kJ/mol C E + 3D ∆H = +64.8 kJ/mol Suppose the first equation is revers...

Q: It has been determined that the body can generate 5500 kJ of

It has been determined that the body can generate 5500 kJ of energy during one hour of strenuous exercise. Perspiration is the body’s mechanism for eliminating this heat. How many grams and how many l...

Q: Use the average atomic masses given inside the front cover of this

Use the average atomic masses given inside the front cover of this book to calculate the number of moles of the element present in each of the following samples. a. 4.95 g of neon b. 72.5 g of nicke...

Q: Which of the following reactions is/are endothermic? a

Which of the following reactions is/are endothermic? a. CO2(s) CO2(g) b. NH3(g) NH3(l) c. 2H2(g) + O2(g) 2H2O(g) d. H2O(l) H2O(s) e. Cl2(g...

Q: A swimming pool, 10.0 m by 4.0

A swimming pool, 10.0 m by 4.0 m, is filled with water to a depth of 3.0 m at a temperature of 20.2 °C. How much energy is required to raise the temperature of the water to 24.6 °C?

Q: Calculate ∆H for the reaction N2H4(l) +

Calculate ∆H for the reaction N2H4(l) + O2(g) N2(g) + 2H2O(l) given the following data:

Q: The “Chemistry in Focus” segment Atmospheric Effects discusses the greenhouse

The “Chemistry in Focus” segment Atmospheric Effects discusses the greenhouse effect. How do the greenhouse gases CO2, H2O, and CH4 have an effect on the temperature of the atmosphere?