Answer:
<h3>A) a chemical change started immediately and finished at 8 minutes!!</h3>
Explanation:
it is stated that the substance <em>slowly </em>starts turning blue, not that it suddenly started changing!! and, this couldn't be a non-chemical change because there are very few chemicals that can turn a completely different color when the two substances were the same color!!! ^_^ please let me know if messed anything up
Atomic number is your answer.
Plate tectonics is the theory that Earth's crust is composed of many plates that are moving slowly over time.
Your answer is D. :)
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%
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