Answer:
First, the microwaves transmit kinetic energy to the water molecules of the food, heating the water molecules. Only, those that are not very deep into the food.
Second, the hot water molecules transmit heat by conduction to the other parts of the food.
Explanation:
1) Microwaves are a form of electromagnetic radiation. The same as any wave, they carry energy.
2) The wave length of microwaves are in the range of 0.001 mm to 1 m (shorter than radio waves and longer than infrared)
3) The microwaves of an oven, used to heat food, have a wave length aroun 12 cm.
4) The microwaves transmit energy to the water molecules in the food, by increasing the kinetic energy of water molecules. As result, the water molecules get hotter. Microwaves only penetrate about 1 cm inside the food (a potato for example) and from that the heat is transferred by conduction to the inner parts of the food.
Answer:
Explanation:
Accoding to the First Law of Thermodynamics, the heat released by the water melts a portion of ice. That is to say:
The amount of ice that is melt is:
Answer: The final pressure will decrease ad the value is 85 kPa
Explanation:
To calculate the final pressure of the system, we use the equation given by Gay-Lussac Law. This law states that pressure of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
where,
are the initial pressure and temperature of the gas.
are the final pressure and temperature of the gas.
We are given:
Putting values in above equation, we get:
Hence, the final pressure will decrease ad the value is 85 kPa
Answer:
Supersaturated
Explanation:
The tea has absorbed and dissolved as much sugar as it could. If there is sugar left at the bottom, it means the solution is supersaturated because it can't absorb any more.
0.781 moles
Explanation:
We begin by balancing the chemical equation;
O₂ (g) + 2H₂ (g) → 2H₂O (g)
21.8 Liters = 21.8 Kgs
To find how many moles are in 28.1 Kg H₂O;
Molar mass of H₂O = 18 g/mol
28.1/18
= 1.56 moles
The mole ratio between water vapor and oxygen is;
1 : 2
x : 1.56
2x = 1.56
x = 1.56 / 2
x = 0.781
0.781 moles
