Answer:
I believe its C.
Explanation:
"Location" can fit in with distance and location depending on the circumstance.
(I apologize if it's wrong)
72 percent is hydrogen. Nuclear fusion converts hydrogen into other elements. The sun is also composed of about 26 percent helium and trace amounts of other elements; oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.
http://www.space.com/17170-what-is-the-sun-made-of.html
The reaction is exothermic, the energy in the bonds has been released to the surroundings (causing the potential energy to go down). The increase in energy in the surrounding heats them up hence exothermic.
the actual yield is the amount of Na₂CO₃ formed after carrying out the experiment
theoretical yield is the amount of Na₂CO₃ that is expected to be formed from the calculations
we need to first find the theoretical yield
2Na₂O₂ + 2CO₂ ---> 2Na₂CO₃ + O₂
molar ratio of Na₂O₂ to Na₂CO₃ is 2:2
number of Na₂O₂ moles reacted is equal to the number of Na₂CO₃ moles formed
number of Na₂O₂ moles reacted is - 7.80 g / 78 g/mol = 0.10 mol
therefore number of Na₂CO₃ moles formed is - 0.10 mol
mass of Na₂CO₃ expected to be formed is - 0.10 mol x 106 g/mol = 10.6 g
therefore theoretical yield is 10.6 g
percent yield = actual yield / theoretical yield x 100%
81.0 % = actual yield / 10.6 g x 100 %
actual yield = 10.6 x 0.81
actual yield = 8.59 g
therefore actual yield is 8.59 g
To determine the proper number of significant figures of a liquid using a graduated cylinder you have to precisely count or measure the indicated number on the cylinder.
