Answer:
Decreased because the method can not distinguish oxygen from the gas added
Explanation:
0.3268 moles of PC15 can be produced from 58.0 g of Cl₂ (and excess
P4)
<h3>How to calculate moles?</h3>
The balanced chemical equation is

The mass of clorine is m(
) = 58.0 g
The amount of clorine is n(
) = m(
)/M(
) = 58/70.906 = 0.817 mol
The stoichiometric reaction,shows that
10 moles of
yield 4 moles of
;
0.817 of
yield x moles of 
n(
) = 4*0.817/10 = 0.3268 mol
To know more about stoichiometric reaction, refer:
brainly.com/question/14935523
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Percent error is the difference between the measured and known value, divided by the known value, multiplied by 100%.
So first, we take our measured value, .299 cm, minus our known value, .225 cm.
.299 cm - .225 cm=.004 cm
Next, we divide that by our known value

Finally, multiply your answer by 100
.0177777778 x 100= 1.77777778 %
Round to three significant figures, and you're done.
=1.78 % error
It is really very important to know where the safety equipments are placed in lab because when we know it then accident wont occur in lab . it will also helps us to feel secure while doing any kinds of experiment
The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.