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:
C₂H₇F₂P
Explanation:
Given parameters:
Composition by mass:
C = 24%
H = 7%
F = 38%
P = 31%
Unknown:
Empirical formula of compound;
Solution :
The empirical formula is the simplest formula of a compound. To solve for this, follow the process below;
C H F P
% composition
by mass 24 7 38 31
Molar mass 12 1 19 31
Number of
moles 24/12 7/1 38/19 31/31
2 7 2 1
Dividing
by the
smallest 2/1 7/1 2/1 1/1
2 7 2 1
Empirical formula C₂H₇F₂P
Concept:
<em><u>Latent Heat of Vaporization</u></em>: It is defined as the amount of heat required to change the state of mater without changing of its temperature.
From the given question, the temperature at the boiling point remained constant despite the continued addition of heat by the Bunsen burner. <em>Actually,</em> this amount of heat is used by water to break the intermolecular bonds between the water molecules in the form of latent heat that converts the liquid state of water into vapor state of water.
Hence, the correct option will be d.<u>The energy was used to break the intermolecular bonds between the water molecules. </u>
Answer:
Warm air rises, resulting in a decrease air pressure.
Explanation:
Tornado is the rapid and violent rotation of column of air which move from the thunderstorm to the ground.
It is formed when there is collision between warm and cold air. The cold air which is more sense than the warm air is pushed over the warm air which result in thunderstorms. The warm air then rises which result in decrease air pressure causing an updraft. The updraft then begin to rotate as there are variations in wind speeds and directions.
