What is the element with 7 protons? They probably also have 7 neutrons. Just a ball park figure guess.
Benzene
- Benzene has low density than the water itself of about 0.9 g/cm³
Low denisty object than the water usually <u>floats on the water</u>.
Another example: orange peel which floats on water has density of about 0.84 g/cm³
Magnesium and chlorine form an ionic bond. Covalent bonds are formed when two or more atoms share electrons between them. ... So two chlorine anions form an ionic bond with one magnesium cation for form MgCl2, a neutral chemical compound.
Answer:
0.272 mol
Explanation:
∆Tb = m × Kb
∆Tb = 85.2°C - 78.4°C = 6.8°C
Kb = 1.22°C/m
mass of ethanol = 48.80 g = 48.80/1000 = 0.0488 kg
Let the moles of non-ionizing solute be y
m (molality) = y/0.0488
6.8 = y/0.0488 × 1.22
y = 6.8×0.0488/1.22 = 0.272 mol
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
