A microwave oven supplies 1.000kj per second.how many min should be set on the microwave in order to heat 250.g of water from 24.3 degrees c to its boiling point?

To solve this problem, we need to determine the amount of energy required to heat the water from its initial temperature to its boiling point. Then we can use the power rating of the microwave oven to calculate the time needed.

Step 1: Calculate the energy required:
The energy required to heat an object can be calculated using the equation:
Q = mcΔT
Where:
Q is the energy required (in joules),
m is the mass of the object (in kilograms),
c is the specific heat capacity of water (4.186 J/g°C), and
ΔT is the change in temperature (in °C).

Given:
Mass of water (m) = 250 g = 0.25 kg
Specific heat capacity of water (c) = 4.186 J/g°C
Initial temperature (T1) = 24.3°C
Final temperature (T2) = boiling point (100°C)

Using the equation above:
Q = (0.25 kg) x (4.186 J/g°C) x (100°C - 24.3°C)
Q = 0.25 kg x 4.186 J/g°C x 75.7°C
Q = 0.787 J

Step 2: Calculate the time required:
We have the energy required and the power rating of the microwave oven. We can use the formula:
Time (t) = Energy (Q) / Power

Given:
Power of the microwave oven = 1.000 kJ/s = 1000 J/s

Using the equation above:
t = 0.787 J / 1000 J/s
t = 0.000787 s

To convert this time value into minutes, divide it by 60:
t (in minutes) = 0.000787 s / 60 s/min
t ≈ 0.00001 min

Therefore, the microwave should be set for approximately 0.00001 minutes or approximately 0.6 seconds (rounding up) to heat 250 g of water from 24.3°C to its boiling point.

Q = mc change T

Divide by the energy rate for time (and you'll have to look up the specific heat for H2O)