In chemistry we did a lab examining iron nails corroding in agar. one of the nails was wrapped in zinc, and the nail did not rust. a whitish substance appeared around the nail, what is the whitish substance?

Zn(OH)₂

Explanation:

Zn is above Fe in the activity series, so it is more readily oxidized:

Zn(s) ⟶ Zn²⁺(aq) + 2e⁻

The zinc ions go into solution.

The electrons travel from the Zn to the surface of the iron nail, where they reduce the water to hydrogen and hydroxide ions.

2H₂O(ℓ) + 2e⁻ ⟶ H₂(g) + 2OH⁻(aq)

Neither the zinc ions nor the hydroxide ions can move far through the gel.

Their concentration builds up around the hail. The ions find each other and form a precipitate.

Zn²⁺(aq) + 2OH⁻(aq) ⟶  Zn(OH)₂(s)

i'm assuming that it's c.) red bank..

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.