I think B. is the correct answer i hope i helped
Answer:

so the 17 is the wavelength
<span>Scientific notation is the standardized way to
represent any number as the product of a real number and a power of ten. Apply Avogadro's constant which is 6.023x10^23 molecules per mole.
20x10^22 molecules / </span>6.023x10^23 molecules per mole = 0.33 moles.
Answer:
When red cabbage is treated with an acid or a base, it produces anthocyanin, a water-soluble pigment that changes color. In acidic situations with a pH less than 7, the pigment turns red, whereas in alkaline (basic) situations with a pH more than 7, the pigment turns bluish-green.
Explanation:
Hexane formula is C₆H₁₄
combustion reaction with O₂ is as follows;
C₆H₁₄ + 19/2O₂ ----> 6CO₂ + 7H₂O
to get whole number coefficients lets multiply by 2
2 C₆H₁₄ + 19 O₂ ----> 12 CO₂ + 14 H₂O
the stoichiometry of C₆H₁₄ to O₂ is 2 :19
2 moles of C₆H₁₄ reacts with 19 mol of O₂
both of these 2 reactants could be fully used up if the amounts are present in the correct stoichiometry or one reactant could be in excess and other could be the limiting reactant. Limiting reactant is when the reactant is fully consumed, products formed depends on this reactant.
amount of C₆H₁₄ moles - 1.72 g / 86.18 g/mol = 0.0200 mol
amount of O₂ moles - 1.8 g / 32 g/mol = 0.056 mol
if hexane is limiting reactant
2:19 ratio , number of O₂ moles - 0.0200/2 *19 = 0.19
but 0.19 moles of O₂ aren't present, this means that O₂ is limiting reactant
stoichiometry of O₂ to CO₂ is 19:12
if 19 moles of O₂ is consumed - 12 mol of CO₂ produced
then 1 mol of O₂ - gives 12/19 mol of CO₂
therefore 0.056 of O₂ - gives 12/19 * 0.056 mol
= 0.035 mol of CO₂
then mass of CO₂ = 0.035 mol * 12 g/mol
= 0.42 g