Hey there!
theoretical yield = (87* 100 ) / 60 = 145 g of phosphorous pentachloride
the reaction for this process is :
molar mass P2O5 => 239.2125 g/mol
molar mass P4 => 123.90 g/mol
molar mass Cl2 => 70.9060 g/mol
P4 + 5 Cl2 --------------> 2 P2Cl5
moles of P2O5 :
145 g / 239.2125 => 0.6062 moles of P2O5
Therefore:
moles of P4 = 0.6062 mol / 2 => 0.3031 moles
moles of Cl2 = 5/2 * 0.6062 mol = 1.5154 moles
mass of P4 ( phosphours ) = 0.3031 mol * 123.90 => 37.554 grams
mass of Cl2 ( chlorine ) = 1.5154 mol * 70.9060 => 107.45 grams
Hope That helps!
First one is a
the
second one is b
Answer: There are 0.499 moles present in 
molecules of Boron trichloride.
Explanation:
According to mole concept, there are 
molecules present in 1 mole of a substance.
Hence, number of moles present in molecules are as follows.
Thus, we can conclude that there are 0.499 moles present in molecules of Boron trichloride.
He improved and followed from the works of Luigi Galvani, which used a 'frog galvanoscope' as a prototype of measuring current. He recognized that a compass could actually measure current, given that it is placed near coil of wire.
Answer:
Explanation:
To solve problems like this, the very first thing to do is to write out the balanced equation for the process. The reaction is
Zn(s) + HCl(aq) → ZnCl2(aq) + H2(g)
and the balanced equation is
Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g)
So, by examining the stoichiometry, you can see that for every mole of Zn, two moles of HCl will be required. In turn, we need to know the number of moles of Zn is represented by 10.4 g. The molecular weight of Zn is 65.38 g/mol so
moles of Zn = 10.4 g/65.38 g/mol = 0.159 moles
and, twice as many moles of HCl is required so
# of moles of HCl required = 2 * 0.159 = 0.318 moles
