A block of copper at a temperature of $50^{\circ} \mathrm{C}$ is placed in contact with a block of aluminum at a temperature of $45^{\circ} \mathrm{C}$ in an insulated container. As a result of a transfer of 2500 J of energy from the copper to the aluminum, the final equilibrium temperature of the two blocks is $48^{\circ} \mathrm{C}.$ What is the approximate change in the entropy of the Universe?

Identify Cause and Effect While federal grants of land were common during the 19th century, cash grants-in-aid were not made until the mid-20th century. What was the reason for this change?

A 50-g block of copper (one mole has a mass of 63.5 g) at a temperature of $35^{\circ} \mathrm{C}$ is put in contact with a 100-g block of aluminum (molar mass 27 g) at a temperature of $20^{\circ} \mathrm{C}.$ The blocks are inside an insulated enclosure, with little contact with the walls. At these temperatures, the high-temperature limit is valid for the specific heat. Calculate the final temperature of the two blocks. Do NOT look up the specific heats of aluminum and copper; you should be able to figure them out on your own.

Find an expression for the change in entropy when two blocks of the same substance and of equal mass, one at the temperature $T_{h}$ the other at $T_{e},$ are brought into thermal contact and allowed to reach equilibrium. Evaluate the change in entropy for two blocks of copper, each of mass 500 g, with $C_{pm}=24.4\ \mathrm{JK}^{-1}\ \mathrm{mol}^{-1},$ taking $T_{\mathrm{h}}=500 \mathrm{K}$ and $T_{e}=250 \mathrm{K}.$

What is the difference between the standard heat of formation and the standard heat of reaction?

The pressure of a gas is directly proportional to its temperature in kelvins. Using $P_1, P_2, T_1,$ and $T_2,$ write a mathematical equation that expresses this relationship.

$$5\times4=20$$

write an equation:

___ times as many as ___ is ___.

How might the incentive fee of a hedge fund affect the manager’s proclivity to take on high-risk assets in the portfolio?

Write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true. ____ Reproductive isolation occurs when members of two populations do not interbreed and produce fertile offspring.

An electron is located at $\langle 0.8,0.7,-0.8\rangle \mathrm{m} .$ You need to find the electric field at location $\langle 0.5,1,-0.5\rangle \mathrm{m},$ due to the electron. What is the vector $\vec{r} ?$

Imagine you are traveling with your family from the southern tip of Texas to the Mexican Plateau. What major river would you see during your travels? Explain how you visualize this body of water as you read a map, and then explain how this body of water would appear if you were to fly over it during your trip.

The ratio of the mass of O to the mass of N in $N_2O_3$ is 12:7. Another binary compound of nitrogen has a ratio of O to N of 16:7. What is its formula? What is the ratio of O to N in the next member of this series of compounds?

Name three types of treatment for drug addiction.

Select a collection of numbers arbitrarily from a newspaper or magazine and record the first digit (the first nonzero digit if it is a decimal less than 1). Do the numbers appear to follow Benford's law?