Answer:
Explanation:
For a flower to appear blue, "it needs to be able to produce a molecule that can absorb very small amounts of energy," in order to absorb the red part of the spectrum, Kupferschmidt said.
Answer:
335 Joules kJ of heat will be released
Explanation:
Given the balanced equation:
8 Al (s) + 3 Fe3O4 (s) ----------> 4 Al2O3 (s) + 9 Fe(s),
ΔH = -3350*KJ/mol rxn
This is the heat released when 8 moles of Al react with 3 mol Fe3O4.
We then need to calculate the moles of reactants, verify if there is a limiting reagent and proceed to answer the question based on the soichiometry of the reaction.
Atomic weight Al = 26.98 g/mol Molecular Weight Fe3O4 = 231.53 g/mol
mol Al = 47.6 g/26.98 g/mol = 1.76 mol
mol Fe3O4 = 69.12 g/ 231.53 g/mol = 0.30 mol
Limiting reagent calculation:
8 mol Al / 3 mol Fe3O4 x 0.30 mol Fe3O4 = 0.80 mol Al are required and we have 1.76 mol, therefore Fe3O4 is the limiting reagent
Amount of Heat
-3350 kJ/ 3 mol Fe3O4 x 0.30 mol Fe3O4 = -335.00 kJ
Ba(OH)2 is an basic solution. It has more OH- ions than H+ ions. pOH should be calculated to find out its pH
The reaction is
Ba(OH)2 ⇒ Ba2+ (aq) + 2 OH-(aq)
One mole barium hydroxide releases 2 moles hydroxide ions.
Use that ratio to calculate molarity (M) of OH- ions [OH-]. The ratio is 1:2.
0.10 M Ba(OH)2 release 2*0.10 M= 0.02 M OH- ions
[OH-]= 0.02
pOH= - log [OH-] = - log 0.02 = 1.7
Thats not the answer! We found pOH of the solution before titration.
pH and pOH relationship is shown by formula of pH+pOH= 14
pH= 14-pOH
pH= 14-1.7= 12.3
Answer: D : A is 3 : 2.
Explanation:
The law of definite proportion is being used here. The law states that a given compound always has the same proportion of its constituent elements by mass.
2a + b = c + 3d
This actually means that, two moles of “a” react with a mole of “b” to produce a mole of “c” and 3 moles of “d”
Using the concept of stoichiometry coefficients of d and a
d:a = 3:2
Answer: CORRECT answer is A
Cl/S\Cl
Explanation:
A P EX