Answer:
454.3 g.
Explanation:
1.0 mol of CaO liberates → – 64.8 kJ.
??? mol of CaO liberates → - 525 kJ.
∴ The no. of moles needed = (1.0 mol)(- 525 kJ)/(- 64.8 kJ) = 8.1 mol.
<em>∴ The no. of grams of CaO needed = no. of moles x molar mass</em> = (8.1 mol)(56.077 g/mol) = <em>454.3 g.</em>
Answer:
Ionic Compounds have high boiling and melting points as they're very strong and require a lot of energy to break. The electrostatic forces of attraction between oppositely charged ions lead to the formation of ions. Ionic compounds form crystals. These compounds are brittle and break into small pieces easily.
Explanation:
Because the moon orbits the earth and when the moon gets in front of the sun it blocks the sunlight and then it becomes night
Answer:
The pressure is 5.62 atm.
Explanation:
An ideal gas is a theoretical gas that is considered to be composed of randomly moving point particles that do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case:
- P= ?
- V= 5.005 L
- n= 1.255 mol
- R= 0.082

- T= 273.5 K
Replacing:
P* 5.005 L= 1.255 mol* 0.082
*273.5 K
Solving:

P= 5.62 atm
<u><em>The pressure is 5.62 atm.</em></u>