How many calories are needed to raise the temperature from 20 degrees Celsius to 40 degrees Celsius for 200g of water?

Hi!

The answer is 4000 calories

I know 1 calories is the energy to raise 1g of water by 1 degree Celsius so for 200g we need 200 * 20 = 4000 calories

But I couldn’t find this result by using the q=mc(deltaT) formula and I don’t understand why:

q=0,2kg * 4 * 20 kelvins

= 16000 joules

I’m not sure about the formula 1kcal=4000J because then I find 4cal as final result

What is my error?

Thank you!