Aurelie is doing a lab in her chemistry class. her teacher defined a calorie as the amount of energy needed to raise the
temperature of one gram of water one degree celsius. aurelie has measured 300 grams of water into a beaker and
recorded its initial temperature as 20°c
how many calories does aurelie need to increase the temperature of the water to 25° celsius? give your answer in calories and
calories.
a. 1.500 calories or 1.50 calories
b. 1.500 calories or 150.0 calories
c. 1,500 calories or 15.0 calories
d. 1.500 calories or 1.50 calories

1.50 cal

Explanation:

Given data:

Mass of water = 300 g

Initial temperature = 20 °C

Final temperature = 25 °C

Calories needed = ?

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Solution:

ΔT  = T2 - T1

ΔT  = 25 °C - 20°C

ΔT  =  

Q = m.c. ΔT

Q = 300 g . 4.18j/g. °C . 5°C

Q = 6270 J

J calories:

6270 / 4184 = 1.50 cal

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.