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3 years ago

Which of the following best defines one mole of a substance?

Chemistry

1 answer:

AlexFokin [52]3 years ago

4 0

Answer: D. Amount of substance present in Avogadro‘s number of particles of the substance

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 Liters at STP, contains avogadro's number $6.023\times 10^{23}$ of particles and weighs equal to the molecular mass of that substance.

A mole is defined as the amount of substance that contains Avogardro number of the substance. Avogadro's number is given by $6.022\times 10^{23}$ .

$1mole=6.022\times 10^{23}$ particles

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Aluminum reacts with sulfur gas to produce aluminum sulfide. a) What is the limiting reactant? What is the excess reagent? b) Ho

Sophie [7]

Answer:

a) Limiting: sulfur. Excess: aluminium.

b) 1.56g Al₂S₃.

c) 0.72g Al

Explanation:

Hello,

In this case, the initial mass of both aluminium and sulfur are missing, therefore, one could assume they are 1.00 g for each one. Thus, by considering the undergoing chemical reaction turns out:

$2Al(s)+3S_2(g)\rightarrow 2Al_2S_3(s)\\$

a) Thus, considering the assumed mass (which could be changed based on the one you are given), the limiting reagent is identified as shown below:

$n_S^{available}=1.00gS_2*\frac{1molS_2}{64gS_2} =0.0156molS_2\\n_S^{consumed\ by \ Al}=1.00gAl*\frac{1molAl}{27gAl}*\frac{3molS_2}{2molAl}=0.0556molS_2$

Thereby, since there 1.00g of aluminium will consume 0.0554 mol of sulfur but there are just 0.0156 mol available, the limiting reagent is sulfur and the excess reagent is aluminium.

b) By stoichiometry, the produced grams of aluminium sulfide are:

$m_{Al_2S_3}=0.0156molS_2*\frac{2molAl_2S_3}{3molS_2} *\frac{150gAl_2S_3}{1molAl_2S_3} =1.56gAl_2S_3$

c) The leftover is computed as follows:

$m_{Al}^{excess}=(0.0556-0.0156)molS_2*\frac{2molAl}{3molS_2}*\frac{27gAl}{1molAl} =0.72 gAl\\$

NOTE: Remember I assumed the quantities, they could change based on those you are given, so the results might be different, but the procedure is quite the same.

Best regards.

7 0

2 years ago

Which of these best explains why a paper clip can float on water? A)Water has a very high specific heat.

stiks02 [169]

Answer:

The answer is d. water molecules near the surface produce more buoyant force than water molecules within the liquid

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2 years ago

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Do you know how to do this? if you have 4 grams of carbon-14, how much carbon 14 remains after 11,460 years? the half life is 5,

Delvig [45]

Carbon dating has given archeologists a more accurate method by which they can determine the age of ancient artifacts. The halflife of carbon 14 is 5730 ± 30 years, and the method of dating lies in trying to determine how much carbon 14 (the radioactive isotope of carbon) is present in the artifact and comparing it to levels

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2 years ago

The 54.9-g sample of the compound X2O7 contains 33.6 g of oxygen atoms. What is the molar mass of element X?

vazorg [7]

Mass of X₂O₇ = 54,9g

2x + 33,6g = 54,9g
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2x = 21,3g | :2
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2 years ago

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A water bath in a physical chemistry lab is 1.85m long, 0.810m wide and 0.740m deep. If it is filled to within 2.57 in from the

jenyasd209 [6]

Answer:

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