Answer:
The sign of \Delta GΔG is negative.
The sign of \Delta HΔH is negative.
The sign of \Delta SΔS is negative.
Explanation:
The water vapor is adsorbed on silica gel due to strong hydrophilicity of silica get towards the water.
The thermodynamic properties of adsorbate and adsorbent changes after adsorption. Silica gel is very porous and hydrophilic, thus, it absorbs the water from the shoe box.
The adsorption process occurs spontaneously, therefore Delta G < 0.
When adsorption occurs, bonds are formed between water molecules and SiO2, and the bond formation process is exothermic (heat is released).
Thus, Delta H < 0.
The water molecules become immobilized on the surface when adsorption occurs, thus, entropy/disorder decreases.
So, Delta S < 0.
Answer:
nNaOH = 0,2 mol
Trong hỗn hợp các chất đề bài cho chỉ có phenol tác dụng với NaOH
C6H5OH + NaOH → C6H5ONa + H2O
0,2 ← 0,2 (mol)
⟹ mphenol = 0,2.94 = 18,8 gam
⟹
%mC6H5OH=18,8/28,9 x100%= 65,05%
Explanation:
Answer:
The partial pressure of the other gases is 0.009 atm
Explanation:
Step 1: Data given
Air is about 78.0% nitrogen molecules and 21.0% oxygen molecules and 1% of other gases.
The atmospheric pressure = 0.90 atm
Step 2: Calculate mol fraction
If wehave 100 moles of air, 78 moles will be nitrogen,
21 moles will be oxygen, and 1 mol will be other gases.
Mol fraction = 1/100 = 0.01
Step 3: Calculate the partial pressure of the other gases
Pgas = Xgas * Ptotal
⇒ Pgas = the partial pressure = ?
⇒ Xgas = the mol fraction of the gas = 0.01
⇒Ptotal = the total pressure of the pressure = 0.90 atm
Pgas = 0.01 * 0.90 atm
Pgas = 0.009 atm
The partial pressure of the other gases is 0.009 atm
M=f/a m=129000N/84m/s/s=1535.714286kg/m/s/s
