Thank you for the free 15 points .
Answer:
Explanation:
We want to convert from moles to grams, so we must use the molar mass.
<h3>1. Molar Mass</h3>
The molar mass is the mass of 1 mole of a substance. It is the same as the atomic masses on the Periodic Table, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
We are given the compound PI₃ or phosphorus triiodide. Look up the molar masses of the individual elements.
- Phosphorus (P): 30.973762 g/mol
- Iodine (I): 126.9045 g/mol
Note that there is a subscript of 3 after the I in the formula. This means there are 3 moles of iodine in 1 mole of the compound PI₃. We should multiply iodine's molar mass by 3, then add phosphorus's molar mass.
- I₃: 126.9045 * 3=380.7135 g/mol
- PI₃: 30.973762 + 380.7135 = 411.687262 g/mol
<h3>2. Convert Moles to Grams</h3>
Use the molar mass as a ratio.
We want to convert 3.14 moles to grams, so we multiply by that value.
The units of moles of PI₃ cancel.
<h3>3. Round</h3>
The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we calculated, that is the tens place.
The 2 in the ones place tells us to leave the 9.
3.14 moles of phosphorous triiodide is approximately equal to <u>1290 grams of phosphorus triodide.</u>
Answer:
Total partial pressure, Pt = 821 mm Hg
Partial pressure of Helium, P1 = 105 mm Hg
Partial pressure of Nitrogen, P2 = 312 mm Hg
Partial pressure of Oxygen, P3 = ? mm Hg
According to Dalton's law of Partial pressures,
Pt = P1 + P2 + P3
So, <u>P3 = 404 mm Hg</u>
Answer:
Explanation:
The melting point of a substance is the temperature at which its melt. The state of a substance is dependent on it's melting temperature. Generally, melting point above 25 °C is a solid.
This means phenol is a solid
Duodecane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of 216 °C means it would require higher temperature to boil it. Since 25 °C is less than 216 °C it means that it would remain in the liquid state.
Methane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of -164 °C means it boils easily even at very low temperatures. Since 25 °C is greater than -164 °C it means that it would exist in the gaseous state
TLDR: The kinetic energy is determined to be zero.
Kinetic energy is energy of motion; when an object is moving (i.e. it has speed or velocity), it has some amount of kinetic energy. The equation itself looks like so:
KE=1/2(m)(v)^2,
where "m" represents the mass of the object and "v" represents the objects speed or velocity. In this example, the ball has stopped, meaning it has no speed/velocity. This means that the final kinetic energy is determined to be zero or none, due to the lack of motion. Mathematically, you can see this by substituting "0" in for "v" (the ball is stopped):
KE=1/2(m)(v)^2
KE=1/2(m)(0)^2
KE=1/2(m)*0
KE=1/2*0
KE=0 J,
or zero kinetic energy.
Hope this helps! :)
