I’m not sure but I think it’s 2-7-4 because the numbers should still add up to 13.(hope it helped)
Water containing carbonic acid and calcium
1) Excess reagent
1 mol N2 / 3 mol H2
6.0 mol N2 *3 mol H2 / 1 mol N2 = 18 mol H2
18mol H2 > 12 mol H2 => H2 is limiting (you need 18 mol H2 to use all the 6 mol N2), then N2 is in excees.
12.0 mol H2 * 1mol N2/ 3 mol H2 = 4 mol N2 is the quantity that will react, then the excess is 6 mol N2 - 4 mol N2 = 2 mol N2
2) NH3 produced
12 mol H2 * [2 mol NH3 / 3 mol H2] = 8 mol NH3
Aslso, 4 mol N2 *[2molNH3 / 1 molN2] = 8 mol NH3, the same result.
3) Yield
80% * 8 mol NH3 = 6.4 mol NH3
Wavelength of the light is 2.9 × 10⁻⁷ m.
<u>Explanation:</u>
Planck - Einstein equation shows the relationship between the energy of a photon and its frequency, and they are directly proportional to each other and it is given by the equation as E = hν,
where E is the energy of the photon
h is the Planck's constant = 6.626 × 10⁻³⁴ J s
ν is the frequency
From the above equation, we can find the frequency by rearranging the equation as,
ν =
= 
Now the frequency and the wavelength are in inverse relationship with each other.
ν × λ = c
It can be rearranged to get λ as,
λ = c / ν
= 
So wavelength is 2.9 × 10⁻⁷ m.
Answer:
it’s mass was greater than when it started
Explanation:
When a metal is coated with another metal, the plating metal deposits on the plated metal. Usually, the plating metal functions as the anode while the plated metal functions on the cathode. The anode metal is oxidized and reduced at the cathode and become deposited on the cathode material. This increases the mass of the cathode. Hence the mass of the silver/gold product is greater than the mass of silver at the beginning of the electroplating process.