Question

How many joules are needed to warm 675 grams of water (specific heat= 4.186 J/g degrees Celsius) from 12 degrees Celsius to 85 degrees Celsius?

Answer 1

Answer:

206,265.15 Joules are needed to warm 675 grams of water from 12 degrees Celsius to 85 degrees Celsius.

Explanation:

Between heat and temperature there is a direct proportionality relationship, where the constant of proportionality depends on the substance that constitutes the body. So, the equation that allows you to calculate heat exchanges is:

Q = c * m * ΔT

Where Q is the heat exchanged for a body of mass m, constituted by a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

• Q=?
• c=$4.186 \frac{J}{g*degrees Celsius}$

• m=675 g
• ΔT=Tfinal-Tinitial=85 degrees Celsius - 12 degrees Celsius= 73 degrees Celsius.

Replacing:

$Q=4.186 \frac{J}{g*degrees Celsius}*675 g*73 degrees Celsius$

Resolving you get:

Q=206,265.15 J

206,265.15 Joules are needed to warm 675 grams of water from 12 degrees Celsius to 85 degrees Celsius.

Answer 2

85-12 = 73 degrees needed
4.186 J/degree Celsius, so 
73 degrees * 4.186 J/degree = 305.578 J to raise 1 gram 73 degrees
there are 675 grams, so 305.578 * 675 = 206265.15 J

2.06 x 10^5 J are needed