Answer:
Choose any of these and it should be correct:
-atmospheric science
-environmental science
-climate science
-biology
-astronomy
-human physiology and medicine
Explanation:
I just had this question on edgenuity, this is what came up as correct. I hope this helps
Maybe
A. 400 ml of 5.0% glucose solution
The mass percent of potassium chloride is 1.386%
<u><em>calculation</em></u>
mass percent = actual mass/ Theoretical mass x 100
Actual mass = 9.35 g
Theoretical mass is calculated as below
Step 1 : write the equation for reaction
KCl + H₂O → KOH + HCl
Step 2: find the moles of H₂O
moles = mass÷ molar mass
The molar mass of H₂O = (2 x1 ) +(16) = 18 g/mol
moles is therefore = 162.98 g÷ 18 g/mol =9.054 moles
Step 3: use the mole ratio to determine the moles of KCl
KCl: H₂O is 1:1 therefore the moles of KCl is also = 9.054 moles
Step 4: find the theoretical mass of KCl
mass = moles x molar mass
from periodic table the molar mass of KCl = 39 +35.5 =74.5 g/mol
mass = 9.054 moles x 74.5 g/mol =674.5 g
Theoretical mass is therefore = 9.35 g/ 674.5 g x 100 = 1.386%
There is only one O=O bond in an O2 molecule, so the energy ΔHO2 required for breakingall the bonds in a mole of O2 molecules is 498 kJ/mol O2 molecules. Calculate the bond energy per mole for forming all the bonds of water molecules, H2O
Answer: Enthalpy of combustion (per mole) of
is -2657.5 kJ
Explanation:
The chemical equation for the combustion of butane follows:

The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(8\times \Delta H^o_f_{CO_2(g)})+(10\times \Delta H^o_f_{H_2O(g)})]-[(1\times \Delta H^o_f_{C_4H_{10}(g)})+(4\times \Delta H^o_f_{O_2(g)})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%288%5Ctimes%20%5CDelta%20H%5Eo_f_%7BCO_2%28g%29%7D%29%2B%2810%5Ctimes%20%5CDelta%20H%5Eo_f_%7BH_2O%28g%29%7D%29%5D-%5B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7BC_4H_%7B10%7D%28g%29%7D%29%2B%284%5Ctimes%20%5CDelta%20H%5Eo_f_%7BO_2%28g%29%7D%29%5D)
We are given:

Putting values in above equation, we get:
![\Delta H^o_{rxn}=[(8\times -393.5)+(10\times -241.82)]-[(2\times -125.6)+(4\times 0)]\\\\\Delta H^o_{rxn}=-5315kJ](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%288%5Ctimes%20-393.5%29%2B%2810%5Ctimes%20-241.82%29%5D-%5B%282%5Ctimes%20-125.6%29%2B%284%5Ctimes%200%29%5D%5C%5C%5C%5C%5CDelta%20H%5Eo_%7Brxn%7D%3D-5315kJ)
Enthalpy of combustion (per mole) of
is -2657.5 kJ