Write a balanced half-reaction for the reduction of dichromate ion cr2o−27 to chromium ion cr 3 in basic aqueous solution. be sure to add physical state symbols where appropriate.

Explanation:

When electrons are added in a reaction then it means reduction is taking place. Whereas removal of electrons from a chemical reaction is known as oxidation.  

Oxidation state of chromium in is +6. So, its reduction half-reaction will be as follows.

Since it is given that reaction is taking place in basic solution. So, we add on reactant side and on the product side.

Now balancing Cr atom and charges on both sides, we get the following.

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.