Question

If the specific heat of a solution is 4.18 J/goC, and you have 296 mL (1.03 g/mL) which increases in temperature by 6.9 degrees, how many kilojoules did the solution absorb?

Answer 1

Answer:

Q = 8.8 kJ

Explanation:

Step 1: Data given

The specific heat of a solution = 4.18 J/g°C

Volume = 296 mL

Density = 1.03 g/mL

The temperature increases with 6.9 °C

Step 2: Calculate the mass of the solution

mass = density * volume

mass = 1.03 g/mL * 296 mL

mass = 304.88 grams

Step 3: Calculate the heat

Q = m*c*ΔT

⇒ with Q = the heat in Joules = TO BE DETERMINED

⇒ with m = the mass of the solution = 304.88 grams

⇒ with c = the specific heat of the solution = 4.18 J/g°C

⇒ with ΔT = the change in temperature = 6.9 °C

Q = 304.88 g * 4.18 J/g°c * 6.9 °C

Q = 8793.3 J = 8.8 kJ

Q = 8.8 kJ

Answer 2

Taking into account the definition of calorimetry and density, the solution absorbed 8.8 kJ.

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

There is a direct proportional relationship between heat and temperature. The constant of proportionality depends on the substance that constitutes the body as on its mass, and is the product of the specific heat by the mass of the body.

So, the equation that allows calculating heat exchanges is:

Q = c×m×ΔT

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

On the other hand, density is a quantity that allows us to measure the amount of mass in a certain volume of a substance. Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:

$density=\frac{mass}{volume}$

In this case, you know:

• density= 1.03 $\frac{g}{mL}$
• mass= ?
• volume= 296 mL

Replacing:

$1.03 \frac{g}{mL} =\frac{mass}{296 mL}$

Solving:

mass= 1.03 $\frac{g}{mL}$× 296 mL

mass=304.88 g

So, you know:

• c= 4.18 $\frac{J}{gC}$
• mass= 304.88 g
• ΔT= 6.9 C

Replacing in the equation that allows calculating heat exchanges:

Q= 4.18 $\frac{J}{gC}$ × 304.88 g× 6.9 C

Solving:

Q= 8,793.35 J= 8.799335 kJ ≅ 8.8 kJ (being 1,000 J= 1 kJ)

Finally, the solution absorbed 8.8 kJ.

Learn more about

• density:

1. brainly.com/question/952755?referrer=searchResults
2. brainly.com/question/1462554?referrer=searchResults

• calorimetry:

1. brainly.com/question/11586486?referrer=searchResults
2. brainly.com/question/24724338?referrer=searchResults