5. The heat of combustion of a sample of coal is 5500 cal/g. What quantity of this coal must be burned to heat 500.0 g of water from 20.0°C to 90.0°C?

6. The heat of combustion of a sample of coal is 5500 cal/g. What quantity of this coal must be
burned to heat 50.0 g of ice from 20.0°C to 90.0°C?

7. One gram of anthracite coal gives off 7000. cal when burned. How many joules is this?
How many grams of anthracite are required to raise the temperature of 4.0 L of water
from 20.0°C to 100.0°C?

8. A 500.0-g piece of iron is heated in a flame and dropped into 400.0 g of water at 10.0°C.
The temperature of the water rises to 90.0°C. How hot was the iron when it was first
removed from the flame? (Specific heat of iron is 0.473 J/gºC.)

HELP PLEASE
time left (1 hour and 20 mins)
22 points if you help!!