To calculate the amount of heat needed to warm 7.40 g of water by 49°C, you can use the formula for heat energy:
Q = mcΔT
Where:
Q is the heat energy in joules (J)
m is the mass of the substance in grams (g)
c is the specific heat capacity of the substance (water has a specific heat capacity of approximately 4.18 J/g°C)
ΔT is the change in temperature in degrees Celsius (°C)
You have already been given the mass (m) and the change in temperature (ΔT), and you know the specific heat capacity (c) of water.
m = 7.40 g
ΔT = 49°C
c (specific heat capacity of water) = 4.18 J/g°C
Now, plug these values into the formula:
Q = (7.40 g) * (4.18 J/g°C) * (49°C)
Calculate this to find the heat energy required:
Q = 1543.394 J (rounded to three decimal places)
So, you would need approximately 1543.394 joules of heat energy to warm 7.40 g of water by 49°C.