Because a unexpected color change has taken place also a precipitate was formed
P + 3Cl > PCl3
because you need to make sure you have the same amount of chlorine and phosphorus on both sides of the equation
<u>Answer:</u>
<em>5 molecules of oxygen will be present
</em>
<u>Explanation:</u>
<em>In this reaction combustion is taking place hence there must be presence of oxygen in it.
</em>
We don't know the initial amount of carbon molecules in hydrogen molecules present hence the equation goes:-
Mass of fuel 16.74 grams, Mass of carbon dioxide is 1198 gram and water is 0.0654 remaining mass of fuel is 16.70 g. Hence amount of fuel used up is 0.04 gram
<em>
</em>
<em>Weight of products is 0.1852 and weight of oxygen is 0.1452
</em>
<em>No of molecules will be
molecules
</em>
Answer:
is the activity, measured in of a 50 mg sample of 90-Sr.
Explanation:
Half life of the 90-Sr ,
Activity coefficient of the 90-Sr = 

Mass of 90-Sr = 50 mg = 0.050 g
Molecular mass of 90-Sr = 90 g/mol
Moles of 90-Sr =
Number of atom in 0.0005555 moles of 90-Sr:


1 year = 
Activity measured in atoms per seconds:
= Number of atoms × 

