How many coulombs of positive charge are there in 1.2 kg of carbon? twelve grams of carbon contain avogadro's number of atoms, with each atom having six protons and six electrons.

5.78 × 10⁷ C

Explanation:

Given that:

The mass of the carbon = 1.2 kg

Also,

1 kg = 1000 g

So, mass = 1200 g

Molar mass of carbon = 12.0107 g/mol

Moles = Mass taken / Molar mass

So,

Moles = 1200 / 12.0107 moles = 99.91 moles

1 mole of carbon contains = 6.022 × 10²³ atoms

Also, 1 atom of carbon contains 6 positive charge (protons)

So,

99.91 moles of carbon contains = 6.022 × 10²³ × 99.91 × 6  protons

Charge on 1 proton = 1.6 × 10⁻¹⁹ C

So,

Charge of 1.2 kg carbon = 6.022 × 10²³ × 99.91 × 6 × 1.6 × 10⁻¹⁹ C = 5.78 × 10⁷ C

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

i think that the answer is c