When a bond is formed, energy is released into the environment. That is because it is an exothermic reaction, it releases energy. <span />
Answer:
Explanation:
The ideal gas law equation is an equation that relates some of the quantities that describe a gas: pressure, volume and temperature.
The equation is:
where
p is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is the gas constant
T is the absolute temperature of the gas (must be expressed in Kelvin)
Here we want to solve the equation isolating p, the pressure of the gas.
We can do that simply by dividing both terms by the volume, V. We find:
So, we see that:
- The pressure is directly proportional to the temperature of the gas
- The pressure is inversely proportional to the volume of the gas
Answer:
the newspaper one is a chemical change because the chemicals in the paper have reacted with something and turned a different color. the wax one is a physical change because it is a change in the phase of matter, which is always a physical change (still the same substance chemically)
<span>294400 cal
The heating of the water will have 3 phases
1. Melting of the ice, the temperature will remain constant at 0 degrees C
2. Heating of water to boiling, the temperature will rise
3. Boiling of water, temperature will remain constant at 100 degrees C
So, let's see how many cal are needed for each phase.
We start with 320 g of ice and 100 g of liquid, both at 0 degrees C. We can ignore the liquid and focus on the ice only. To convert from the solid to the liquid, we need to add the heat of fusion for each gram. So multiply the amount of ice we have by the heat of fusion.
80 cal/g * 320 g = 25600 cal
Now we have 320 g of ice that's been melted into water and the 100 g of water we started with, resulting in 320 + 100 = 420 g of water at 0 degrees C. We need to heat that water to 100 degrees C
420 * 100 = 42000 cal
Finally, we have 420 g of water at the boiling point. We now need to pump in an additional 540 cal/g to boil it all away.
420 g * 540 cal/g = 226800 cal
So the total number of cal used is
25600 cal + 42000 cal + 226800 cal = 294400 cal</span>
