<span>(1) The atom absorbs energy, and one or more electrons move to a higher electron shell.</span>
Answer:
heated crude oil enters a tall fractionating column , which is hot at the bottom and gets cooler towards the top. vapours from the oil rise through the column. vapours condense when they become cool enough. liquids are led out of the column at different heights.
Explanation:
The ball stops moving because of friction force. Friction is the force that opposes all motion. Therefore, the answer is friction force...
Use stoichiometric ratio to determine which is in excess and which is limiting
Answer:
The total heat required is 4088.6 J
Explanation:
We have three processes which involve heat absorption. We have to calculate the heat of each process and then to calculate the total heat.
1- liquid ethanol is heated from 25ºC (298 K) to the boiling point 78.5ºc (351.5 K). We use specifi heat of liquid ethanol to calculate the heat absorbed in this part:
H1= m x Sh x ΔT
H1= m x Sh x (Tfinal - Tinitial)
H1= 3.95 g x 2.45 J/g.K x (351.5 K -298 K)
H1= 517.7 J
2- State change: liquid ethanol is vaporized it turns gaseous ethanol The process occur at constant temperature (78.5ºC= 351.5 K). We need the molecular weight of ethanol (2 x 14 + 5 + 16 + 1= 46 g/mol) to cancel mol unit:
H2= m x ΔHvap x 1/Mw
H2= 3.95 g x 40.5 KJ/mol x 1 mol/46 g
H2= 3.477 KJ= 3477 J
3- Gaseous ethanol is heated from 78.5ºC to a final temperature of 95ºC (368 K). We use the specific heat of gaseous ethanol:
H3= m x Sh x ΔT
H3= 3.95 g x 1.43 J/g.K x (368 K - 351.5 K)
H3= 93.2 J
The total heat required is calculated as follows:
Htotal= H1 + H2 + H3
Htotal= 517.7 J + 3477.7 J + 93.2 J
Htotal= 4088.6 J
