<span>The first method to determine the chemical composition of a substance in space was using light. By determining red shift in the observed spectrum of light they could determine the elements they were observing. Different elements change the way light behaves and from this scientists can determine the makeup of things such as stars and nebulas.</span>
Answer:
Electromagnetic force, Strong nuclear force, and Weak nuclear force.
Explanation:
Forces acting
electromagnetic force, strong nuclear force, and weak nuclear force. The electromagnetic force keeps the electrons attached to the atom. The strong nuclear force keeps the protons and neutrons together in the nucleus. The weak nuclear force controls how the atom decays.
Answer is: tin and zinc, because they standard potential as less than zero.
Tin and zinc are oxidized to tin and zinc cations (with +2 charge) and hydrogen anions are reduced to hydrogen molecules with neutral charge.
Zn → Zn²⁺ + 2e⁻; 2H⁺ + 2e⁻ → H₂.
<span>Oxidation is increase
of oxidation number and reduction is decrease
of oxidation number.</span>
Answer:
Percent yield = 61.58%
Explanation:
C4H9OH + NaBr + H2SO4 --> C4H9Br + NaHSO4 + H2O
From the reaction;
1 mol of C4H9OH reacts with 1 mol of NaBr and 1 mol of H2SO4 to form 1 mol of C4H9Br
We have to obtain the limiting reagent. We do this by calculatig the mols of each reactant in the reaction;
Number of moles = Mass / Molar mass
C4H9OH; 15 / 74g/mol = 0.2027
NaBr; 22.4 / 102.89 = 0.2177
H2SO4; 32.7 / 98 = 0.3336
In this case, the limiting reagent is C4H9OH, it determines the amount of product formed.
From the stoichometry of the reaction; one mole of C4H9OH forms one mole of C4H9Br. This means 0.2027 mol of C4H9Br was formed.
Mass = Number of moles * Molar mass
Mass of C4H9Br formed = 0.2027 * 137
Mass = 27.77g
Percent yield = (Practical yield / theoretical yeield ) * 100%
Percent Yield = 17.1 / 27.77 * 100
Percent yield = 61.58%
