The specific heat of aluminum is 0.897 J/g•°C. Which equation would you use to calculate the amount of heat needed to raise the temperature of 0.75 g of aluminum from 7°C to 29°C?

A. Q = 0.75 g x 0.385 J/g•°C x 22°C

B. Q = 0.75 g x 0.385 J/g•°C x 29°C

C. Q = 0.75 g x 0.897 J/g•°C x 29°C

D. Q = 0.75 g x 0.897 J/g•°C x 22°C

clearly it is either A or D.

So, is there a numeric factor in there somewhere, or not?

3000cal

The answer is D.

To calculate the amount of heat needed to raise the temperature of a substance, you can use the equation:

Q = m x c x ΔT

Where:
Q = heat energy (in Joules)
m = mass of the substance (in grams)
c = specific heat capacity of the substance (in J/g•°C)
ΔT = change in temperature (in °C)

In this case, you have a mass of 0.75 g of aluminum, a specific heat of 0.897 J/g•°C, and a change in temperature from 7°C to 29°C.

Plugging those values into the equation, the correct equation to use is:

Q = 0.75 g x 0.897 J/g•°C x (29°C - 7°C)

Simplifying the equation, you would get:

Q = 0.75 g x 0.897 J/g•°C x 22°C

Therefore, the answer is option D. Q = 0.75 g x 0.897 J/g•°C x 22°C.