<h2>The number of moles of formaldehyde can be produced by reacting 4.0 moles of methanol with 4.0 moles of oxygen gas is
<u>
8 moles</u></h2>
<u> explanation</u>
write a balanced chemical reaction
that is 2 CH3OH (l) + O2 (g) → 2HCOH (l)+ 2H2O (l)
from the reaction above 2 moles of CH3OH reacted with 1 moles of O2 to form 2 moles of HCOH and two moles of H2O
This imply that O2 is the limiting reagent ,therefore by use of mole ratio between O2 : HCOH which is 1 :2 the moles of HCOH= 2 x4 = 8 moles
Answer: 
Explanation:-
The conversions involved in this process are :
Now we have to calculate the enthalpy change:
![\Delta H=[n\times c_{ice}\times (T_{final}-T_{initial})]+n\times \Delta H_{fusion}+[n\times c_{water}\times (T_{final}-T_{initial})]+n\times \Delta H_{vap}+[n\times c_{steam}\times (T_{final}-T_{initial})]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20c_%7Bice%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D%2Bn%5Ctimes%20%5CDelta%20H_%7Bfusion%7D%2B%5Bn%5Ctimes%20c_%7Bwater%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D%2Bn%5Ctimes%20%5CDelta%20H_%7Bvap%7D%2B%5Bn%5Ctimes%20c_%7Bsteam%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D)
where,
= enthalpy change = ?
m = mass of water = 459 g
= specific heat of ice = 
= specific heat of water = 
= specific heat of steam = 
n = number of moles of water = 
= enthalpy change for fusion = 6.01 KJ/mole = 6010 J/mole
= enthalpy change for vaporization = 40.67 KJ/mole = 40670 J/mole
Now put all the given values in the above expression, we get:
![\Delta H=[25.5mole\times 36.57J/mol^0C\times (0-(-10))^0C]+25.5mole\times 6010J/mole+[25.5mole\times 75.40J/mol^0C\times (100-0)^0C]+25.5mole\times 40670J/mole+[25.5mole\times 36.04J/gmol^0C\times (125-100)^0c]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B25.5mole%5Ctimes%2036.57J%2Fmol%5E0C%5Ctimes%20%280-%28-10%29%29%5E0C%5D%2B25.5mole%5Ctimes%206010J%2Fmole%2B%5B25.5mole%5Ctimes%2075.40J%2Fmol%5E0C%5Ctimes%20%28100-0%29%5E0C%5D%2B25.5mole%5Ctimes%2040670J%2Fmole%2B%5B25.5mole%5Ctimes%2036.04J%2Fgmol%5E0C%5Ctimes%20%28125-100%29%5E0c%5D)
(1kJ = 1000 J)
Therefore, the enthalpy change is
Answer: A) sea arch
Explanation:
A natural arch or sea arch can be defined as a natural bridge which forms with an opening underneath. A natural arch or sea arch is formed when the stacks are subjected to erosion. A stack can be defined as the geological form that is formed by the water wave erosion due to vertical column. The sea arches form inland cliffs, fins and other forms.
Answer:
a. Yes
b. 143.5 mmHg
Explanation:
The vapor pressure is the pressure of the vapor that is in equilibrium with the liquid. At a constant temperature, some molecules of the liquid will vaporize, and then will do pressure at the surface of the liquid.
If the pressure at the container is higher then the vapor pressure, the liquid will evaporate.
a. Let's calculate the pressure at the container by the ideal gas law:
PV = nRT
Where P is the pressure, V is the volume, n is the number of moles, R is the gas constant (62,364 mmHg.mL/mol.K), and T is the temperature.
The molar mass of CH₃I is 142 g/mol
n = mass/ molar mass
n = 0.453/142
n = 0.0032 mol
P*370 = 0.0032*62,364*266
370P = 53,084.24
P = 143.5 mmHg
So, all the liquid will evaporate.
b. Because all liquid evaporates, when the equilibrium is reached, the pressure is the gas pressure: 143.5 mmHg.
Answer:
1. (S,O) < (Se,S) < (C,H) = (H,I) = (H,F) < (Si,Cl) < (K,Br)
Explanation:
The covalent character always increases down the group, this is because ionic character decreases down the group and also electronegativity.
In the same way, Covalent character always decreases across a period because electronegativity increases across a period.
The higher the electronegativity values between the two atoms, the more ionic it will be.
