Answer:
c
Explanation:
The law of conservation clearly states that energy can neither be created nor destroyed
Answer:
Na₂CO₃.
Explanation:
- <em>Le Châtelier's principle</em> states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.
The compound that has a common ion effect is Na₂CO₃.
- When it is added to the solution, it is dissolved to produce Na⁺ and CO₃²⁻ which increases the concentration of CO₃²⁻ that will increase the concentration of the products side, so the reaction will be shifted to the left side to suppress the increase in the concentration of CO₃²⁻.
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
