Answer:
12.6.
Explanation:
- We should calculate the no. of millimoles of KOH and HCl:
no. of millimoles of KOH = (MV)KOH = (0.183 M)(45.0 mL) = 8.235 mmol.
no. of millimoles of HCl = (MV)HCl = (0.145 M)(35.0 mL) = 5.075 mmol.
- It is clear that the no. of millimoles of KOH is higher than that of HCl:
So,
[OH⁻] = [(no. of millimoles of KOH) - (no. of millimoles of HCl)] / (V total) = (8.235 mmol - 5.075 mmol) / (80.0 mL) = 0.395 M.
∵ pOH = -log[OH⁻]
∴ pOH = -log(0.395 M) = 1.4.
∵ pH + pOH = 14.
∴ pH = 14 - pOH = 14 - 1.4 = 12.6.
When you want to melt an ice, you only need the latent energy of fusion, <span>δhfus. We use the given value, then multiply this with the given amount to determine the amount of energy. Since the energy is per mole basis, use the molar mass of ice which is 18 g/mol. The solution is as follows:
</span>ΔH = 5.96 kJ/mol * 1 mol/18 g * 500 g
<em>ΔH = 165.56 kJ</em><span>
</span>
The partial stress of H2 is 737.47 mmHg Let's observe the Ideal Gas Law to find out the whole mols.
We count on that the closed vessel has 1L of volume
- P.V=n.R.T
- We must convert mmHg to atm. 760 mmHg.
- 1 atm
- 755 mmHg (755/760) = 0.993 atm
- 0.993 m.1L=n.0.082 L.atm/mol.K .
- 293 K(0.993 atm 1.1L)/(0.082mol.K /L.atm).
- 293K = n
- 0.0413mols = n
These are the whole moles. Now we are able to know the moles of water vapor, to discover the molar fraction of it.
- P.V=n.R.T
- 760 mmHg. 1 atm
- 17.5 mmHg (17.5 mmHg / 760 mmHg)=0.0230 atm
- 0.0230 m.1L=n.0.082 L.atm/mol.K.293 K(0.0230atm.1L)/(0.082mol.K/L.atm .293K)=n 9.58 × 10 ^ 4 mols = n.
- Molar fraction = mols )f gas/general mols.
- Molar fraction water vapor =9.58×10^ -four mols / 0.0413 mols
- Sum of molar fraction =1
- 1 - 9.58 × 10 ^ 4 × mols / 0.0413 ×mols = molar fraction H2
- 0.9767 = molar fraction H2
- H2 pressure / Total pressure =molar fraction H2
- H2 pressure / 55mmHg = =0.9767 0.9767 = h2 pressure =755 mmHg.
- 737,47 mmHg.
<h3>What is a mole fraction?</h3>
Mole fraction is a unit of concentration, described to be identical to the variety of moles of an issue divided through the whole variety of moles of a solution. Because it's miles a ratio, mole fraction is a unitless expression.
Thus it is clear that the partial pressure of H2 is 737,47 mmHg.
To learn more about partial pressure refer to the link :
brainly.com/question/19813237
<h3 />
Answer:
Hydrogen bonding
Explanation:
As a rule of thumb, "likes dissolve like", meaning polar solutes dissolve in polar solvents and nonpolar solutes in nonpolar solvents. In this case, water is polar (<em>dipolar moment</em> = 1.85 Debye) dissolves methanol which is also polar (<em>dipolar moment</em> = 1.69 Debye). Besides being dipoles, both molecules have atoms of Hydrogen with a covalent bond to more electronegative atoms of Oxygen. When this happens, stronger dipole-dipole interactions appear known as Hydrogen bonding. There is an electrostatic attraction between H (positive charge density) and O (negative charge density).
