Calculate the change in thermal energy when 2kg of water is heated from 20°C to 80°C.​

504000 J

Explanation:

Applying,

Δq = cm(Δt) Equation 1

Where Δq = change in thermal energy, c = specific heat capacity of water,  m = mass of water, Δt = change in temperature.

From the question,

Given: m = 2 kg, Δt = 80-20 = 60°C

Constant; c = 4200 J/kg.°C

Substitute these values into equation 1

Δq = 2(4200)(60)

Δq = 504000 J

Hence the thermal energy is  504000 J

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).