posted by Mark on .
In a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B
2A ---> 3B
How many molecules of substance B are produced when 27.9 g of substance A reacts? the molar mass of substance A is 24.7 g/mol
STEP 1: convert the mass of A to moles
this is what i did :
2mol x 27.9g/24.7g = 2.259109 mol
is it right?
STEP 2 :convert the number of moles of A to the number of moles of B
STEP 3: convert the number of moles of B to molecules of B
You shouldn't multiply by the 2 yet. You will use that in the next step of the problem.
Step 2: Here you will take the moles you got and use the given moles of substance.
1.1296 molA * (3 molB/2 molA)
That will give you the correct number of moles B.
Step 3: Here you use Avogadro's # to find molecules of B.
NOTE: I am not a tutor but I have done problems like this before.