You are given two unknown point charges, q1, and q2. at a point on the line joining them, one third of the way from q1 to q2 the electric field is zero. what can you say about these two charges?

Explanation:

If they were of opposite signs, in the line joining them, the electric field will not be zero at any point, as in all points of this line will be pointing towards the negative charge.

The equation for the electric field produced by a point charge its:

taking in consideration that the electric field its a vector that points radially outward from the point charge, and the equation above only gives us its length.

Now, If we got a zero electric field, that must mean that the electric fields from both charges are, in magnitude, equals. This means:

We also now that the distance to Q1 from this point its one third the distance from Q1 to Q2, this must mean that its 2 times .

We can get ride of the factor that appears on both sides:

And we finally get:

when it gains or loses electrons

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂