Answer:
A supersaturated solution made out of sugar and oil is crystallized on a surface suitable for crystal nucleation such as a stick.
I hope this helps.
Answer:
D) 65.7%
Explanation:
Based on the reaction:
2H2(g)+O2(g)⟶2H2O(l)
<em>2 moles of hydrogen produce 2 moles of water assuming an excess of oxygen.</em>
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To find percent yield of the reaction we need to find theoretical yield (The yield assuming all hydrogen reacts producing water). With theoretical yield and actual yield (32.8g H₂O) we can determine percent yield as 100 times the ratio between actual yield and theoretical yield.
<em>Theoretical yield:</em>
Moles of 5.58g H₂:
5.58g H₂ ₓ (1 mol / 2.016g) = 2.768 moles H₂
As 2 moles of H₂ produce 2 moles of H₂O, if all hydrogen reacts will produce 2.768 moles H₂O. In grams:
2.768 moles H₂O ₓ (18.015g / mol) =
49.86g H₂O is theoretical yield
<em>Percent yield:</em>
Percent yield = Actual yield / Theoretical yield ₓ 100
32.8g H₂O / 49.86g ₓ 100 =
65.7% is percent yield of the reaction
<h3>D) 65.7%
</h3>
Answer:
b.
Explanation:
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Answer:
b) warming up a) wavelength a) blank c) sample
Explanation:
<em>To run a spectrophotometry experiment, begin by </em><em>warming up</em><em> the spectrophotometer and preparing the samples.</em> It is important that the equipment is warmed up for at least 30 minutes before starting the measurements.
<em>Be sure to select the correct </em><em>wavelength</em><em>, then run a measurement on the </em><em>blank</em><em> solution.</em> The selected wavelength depends on the analyte of interest. The black solution contains the same matrix but it doesn´t contain the analyte.
<em>Follow up by running measurements on </em><em>sample</em><em> solutions. Once data is collected, turn off the instrument, clean the area, and discard the samples. </em>The samples are those of unknown concentration that we want to determine.
