Question

A 250 grams sample of an unknown substance was heated from 35 degree Celsius to 50 degree Celsius. The substance absorbed 7,454 J of energy. What is the specific heat of the substance? Identify if the reaction is exothermic or endothermic

Answer 1

Specific heat capacity, c = 1.99J/g°C. The reaction is endothermic because heat is being absorbed.

Step-by-step explanation:

Given the following data;

Mass = 250g

Original temperature, T1 = 35°C

New temperature, T2 = 50°C

Quantity of heat = 7454J

To find the specific heat capacity;

Heat capacity is given by the formula;

`Q = mcdt`

Where;

Q represents the heat capacity or quantity of heat.

• m represents the mass of an object.
• c represents the specific heat capacity of water.
• dt represents the change in temperature.

dt = T2 - T1

dt = 50 - 35

dt = 15°C

Making "c" the subject of formula, we have;

`c = \frac {Q}{mdt}`

Substituting the values into the equation, we have;

`c = \frac {7454}{250*15}`

`c = \frac {7454}{3750}`

Specific heat capacity, c = 1.99J/g°C.

Therefore, the reaction is endothermic because heat is being absorbed (initial temperature is lower than the final temperature).