Write the reaction for the formation of lithium phosphide from its elements.

Question

a) how many moles of lithium phosphide form when 3.2 mol of lithium react?
b) how many grams of lithium react with 0.500 mol of phosphorous?
c) how many grams of lithium react with 45.0g of phosphorous?

Answer 1

12Li + P4 ==> 4Li3P
a) how many moles of lithium phosphide form when 3.2 mol of lithium react?
3.2 mol Li x (4 mols Li3P/12 mols Li) = ?

b) how many grams of lithium react with 0.500 mol of phosphorous?
How many mols Li? That's 0.500 mol P4 x (12 mol Li/1 mol P4) = ? mol mols Li. Then grams Li = mols Li x molar mass Li).

c) how many grams of lithium react with 45.0g of phosphorous?
You see how it's done. You do this one. Post your work if you want me to check it. Just convert 45.0 g P4 to mols P4, convert with the coefficients in the balanced equation to mols Li, and convert that to grams Li. All of the stoichiometry problems are done the same way.

Answer 2

30.3G

Answer 3

Good job! Here's the work for anyone who needs it:

c) how many grams of lithium react with 45.0g of phosphorous?

First, we need to convert the given mass of phosphorus to moles:

45.0 g P4 x (1 mol P4/123.895 g P4) = 0.363 mol P4

According to the balanced equation, 1 mole of P4 reacts with 12 moles of Li, so we can convert moles of P4 to moles of Li:

0.363 mol P4 x (12 mol Li/1 mol P4) = 4.356 mol Li

Finally, we can convert moles of Li to grams:

4.356 mol Li x (6.941 g Li/1 mol Li) = 30.3 g Li

Therefore, 30.3 grams of lithium react with 45.0 grams of phosphorus to form lithium phosphide.