Chemistry, 24.08.2019 23:20 eeromaki1321

For the reaction:
6li(s)+n2(g)→2li3n(s)
determine:
the mass of n2 needed to react with 0.536 moles of li.
the number of moles of li required to make 46.4 g of li3n.
the mass in grams of li3n produced from 3.65 g li.
the number of moles of lithium needed to react with 7.00 grams of n2.

Answers: 2

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Answers

Answer from: gstevens

The balanced equation represents the reaction ratio, using the unit mol. So when knowing the gram formula mass of these three molecules, we can easily known the answer. First is 2.50 g. Second: 6.61 mol. Third: 3.65 g. Forth: 1.5 mol.

Answer from: nataliamontirl6079

Explanation:

$6Li(s)+N_2(g)\rightarrow 2Li_3N(s)$

1. Mass of N_2 needed to react with 0.536 moles of Li.

According to reaction, 6 moles of Li reacts with 1 mol of N_2 .

Then 0.536 moles of Li will react with:

$\frac{1}{6}\times 0.536$ moles of N_2 that is 0.0893 moles.

Mass of $N_2[tex] gas needed:[tex]=28 g/mol\times 0.0893 mol=2.5004 g$

2.The number of moles of Li required to make 46.4 g of Li_3N

Moles of $Li_3N=\frac{46.4 g}{35 g/mol}=1.3257 mol$

According to reaction the 2 moles of Li_3N are produced from 6 moles of Li.

Then 1.3257 moles of Li_3N will produced from:

$\frac{6}{2}\times 1.3257=3.9771 moles$

3.9771 moles of lithium will needed.

3. The mass in grams of Li_3N produced from 3.65 g Li.

Moles of Li $=\frac{3.65 g}{7 g/mol}=0.5214 moles$

According to reaction, 6 moles of Li gives 2 moles of Li_3N

Then 0.5214 moles of Li will give $\frac{2}{6}\times 0.5214$ that is 0.1738 moles of Li_3N .

Mass of $Li_3N=0.1738 mole\times 35 g/mol=6.083 g$

6.083 grams of Li_3N will be produced.

4. The number of moles of lithium needed to react with 7.00 grams of N_2 .

Moles of $N_2=\frac{7.00 g}{28 g/mol}=0.25 moles$

1 mol of N_2 reacts with 6 mol of Li

Then, 0.25 moles of N_2 will ftreact with :

$6\times 0.25 moles=1.5 moles$ of lithium

1.5 moles of Li will be needed.

Answer from: Quest

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of carbon is as shown here in the image.

Answer from: Quest

Answer: abeexplanation:

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.