the answer is option D "people emphasized obtaining knowledge through scientific experiments" (on plato)
A. Combustion since it can’t be nuclear….?
Answer:
= 72.73%
Explanation:
The percentage by mass of an element is given by;
% element = total mass of element in compounds/molar mass of compound × 100
The mass of oxygen in carbon dioxide = 32 g
Molar mass of CO2 = 44 g
Therefore;
% of O2 = 32/44 × 100%
<u>= 72.73%</u>
Answer:
1.
643.21g 1 mol 6.022^23
262.87 g 1 mol
= 1.4735E24 [Mg3(PO4)2]
2.
4.061x10^24 1mol 22.4 (L)
6.022^23 1mol
= 151 liters H2O2
3.
479.3g 1 mol 6.022^23
18.02g 1mol
= 1.60E25 H20 atoms
4.
80.34L 1mol 164.1
22.4L 1mol
588.6g Ca(NO3)2
5.
893.7g 1mol 22.4
44.01g 1mol
= 427 L CO2 or 427.4
6.
5.39 x 10^25 1mol 78.01
6.022^23 1mol
= 6980g Al(OH)3
hope this helps!! :)
When it comes to physical changes like phase changes, there are two types of heat energy: sensible heat and latent heat. Sensible heat is the heat absorbed/released when you heat the substance but it doesn't change phase. An example would be heating lukewarm water. The substance is liquid all throughout. Latent heat, on the other hand, is the heat absorbed/released when there is a phase change. An example would be boiling water, because it changes liquid to vapor.
Hence, for freezing liquid, you use the latent heat, specifically the heat of fusion. The answer should be
2.5 g * (1 mol/18.02 g) * 6.03 kJ/mol = 0.84 kJ/mol
The answer is not in the choices. You only use Hvap if you boil water.
