Boiling point of cyclohexane at 620 mm hg?
Standard atmospheric pressure is 760 mm Hg. Boiling point at 760 mm= 80.74˚C
A liquid boils when its vapor pressure is equal to the atmospheric pressure. The vapor pressure of a liquid is proportional the absolute temperature of the liquid.
As the atmospheric pressure decreases, less vapor pressure is needed to cause the liquid to boil. Less vapor pressure means lower temperature.
The boiling point of cyclohexane at 620 mm Hg is less than 80.74˚C
TRY THAT OR THIS
271.78
Hey there!:
Molar mass Ca(NO2)2 = 132.089 g/mol
Mass of solute = 120 g
Number of moles:
n = mass of solute / molar mass
n = 120 / 132.089
n = 0.0009084 moles of Ca(NO2)2
Volume in liters of solution :
240 mL / 1000 => 0.24 L
Therefore:
Molarity = number of moles / volume of solution
Molarity = 0.0009084 / 0.24
Molarity = 0.003785 M
Hope that helps!
From the chemical formula of sulfuric acid, we can see the molar ratio:
H : S : O
2 : 1 : 4
Now, we convert the mass of hydrogen given into the moles of hydrogen. This is done using
Moles = mass / Mr
Moles = 7.27 / 1
Moles = 7.27
Therefore, the moles will be:
S = 7.27 / 2 = 3.64 moles
O = 7.27 * 2 = 14.54 moles
Now, the respective masses are:
S = 32 * 3.64 = 116.48 grams
O = 16 * 14.54 = 232.64 grams
Answer:
Explanation:
1. Concentration of SO₄²⁻
SrSO₄(s) ⇌ Sr²⁺(aq) +SO₄²⁻(aq); Ksp = 3.44 × 10⁻⁷
0.0150 x
![K_{sp} =\text{[Sr$^{2+}$][SO$_{4}^{2-}$]} = 0.0150x = 3.44 \times 10^{-7}\\x = \dfrac{3.44 \times 10^{-7}}{0.0150} = \mathbf{2.293 \times 10^{-5}} \textbf{ mol/L}](https://tex.z-dn.net/?f=K_%7Bsp%7D%20%3D%5Ctext%7B%5BSr%24%5E%7B2%2B%7D%24%5D%5BSO%24_%7B4%7D%5E%7B2-%7D%24%5D%7D%20%3D%200.0150x%20%3D%203.44%20%5Ctimes%2010%5E%7B-7%7D%5C%5Cx%20%3D%20%5Cdfrac%7B3.44%20%5Ctimes%2010%5E%7B-7%7D%7D%7B0.0150%7D%20%3D%20%5Cmathbf%7B2.293%20%5Ctimes%2010%5E%7B-5%7D%7D%20%5Ctextbf%7B%20mol%2FL%7D)
2. Concentration of Pb²⁺
PbSO₄(s) ⇌ Pb²⁺(aq) + SO₄²⁻(aq); Ksp = 2.53 × 10⁻⁸
x 2.293 × 10⁻⁵
![K_{sp} =\text{[Pb$^{2+}$][SO$_{4}^{2-}$]} = x \times 2.293 \times 10^{-5} = 2.53 \times 10^{-8}\\\\x = \dfrac{2.53 \times 10^{-8}}{2.293 \times 10^{-5}} = \mathbf{1.10 \times 10^{-3}} \textbf{ mol/L}\\\\\text{The concentration of Pb$^{2+}$ is $\large \boxed{\mathbf{1.10 \times 10^{-3}}\textbf{ mol/L}}$}](https://tex.z-dn.net/?f=K_%7Bsp%7D%20%3D%5Ctext%7B%5BPb%24%5E%7B2%2B%7D%24%5D%5BSO%24_%7B4%7D%5E%7B2-%7D%24%5D%7D%20%3D%20x%20%5Ctimes%202.293%20%5Ctimes%2010%5E%7B-5%7D%20%3D%202.53%20%5Ctimes%2010%5E%7B-8%7D%5C%5C%5C%5Cx%20%3D%20%5Cdfrac%7B2.53%20%5Ctimes%2010%5E%7B-8%7D%7D%7B2.293%20%5Ctimes%2010%5E%7B-5%7D%7D%20%3D%20%5Cmathbf%7B1.10%20%5Ctimes%2010%5E%7B-3%7D%7D%20%5Ctextbf%7B%20mol%2FL%7D%5C%5C%5C%5C%5Ctext%7BThe%20concentration%20of%20Pb%24%5E%7B2%2B%7D%24%20is%20%24%5Clarge%20%5Cboxed%7B%5Cmathbf%7B1.10%20%5Ctimes%2010%5E%7B-3%7D%7D%5Ctextbf%7B%20mol%2FL%7D%7D%24%7D)
Hydrogenated vegetable oil is a preservative, thus, the correct option is D. Hydrogenated vegetable oil are used by food industries to prevent fat rancidity in order to give their product a longer shelf life. Hydrogenated oils are very good preservatives because all the enzymatic activities in the oil has been neutralized during the hydrogenating process.
