Composición centecimal de H2SO4

Calculate the vapor pressure of water above a solution prepared by dissolving 28.5 g of glycerin (c3h8o3) in 135 g of water at 3

pshichka [43]

Data:

Solute: 28.5 g of glycerin (C3H8O3)
Solvent: 135 g of water at 343 k.
Vapor pressure of water at 343 k: 233.7 torr.

Quesiton: Vapor pressure of water

Solution:

Raoult's Law: The vapour pressure of a solution of a non-volatile solute is equal to the vapour pressure of the pure solvent at that temperature multiplied by its mole fraction.

Formula: p = Xsolvent * P pure solvent

X solvent = moles solvent / moles of solution

molar mass of H2O = 2*1.0g/mol + 16.0 g/mol = 18.0 g/mol

moles of solvent = 135 g of water / 18.0 g/mol = 7.50 mol

molar mass of C3H8O3 = 3*12.0 g/mol + 8*1 g/mol + 3*16g/mol = 92 g/mol

moles of solute = 28.5 g / 92.0 g/mol = 0.310 mol

moles of solution = moles of solute + moles of solvent = 7.50mol + 0.310mol = 7.810 mol

Xsolvent = 7.50mol / 7.81mol = 0.960

p = 233.7 torr * 0.960 = 224.4 torr

Answer: 224.4 torr

8 0

4 years ago

Determine whether each of the following is a strong acid, a weak acid, or a species with negligible acidity.Drag the appropriate

sp2606 [1]

Answer:

CH₃NH₃⁺ is a weak acid.

HPO₄²⁻ has a negligible acidity.

CH₄ has a negligible acidity.

HNO₂ is a weak acid.

Explanation:

There are 7 strong acids: HCl, HBr, HI, HNO₃, H₂SO₄, HClO₃, HClO₄. The rest of the acids are weak.

CH₃NH₃⁺ is a weak acid, according to the following equation:

CH₃NH₃⁺ ⇄ CH₃NH₂ + H⁺

HPO₄²⁻ can act as an acid or as a base:

Acid reaction: HPO₄²⁻ ⇄ PO₄³⁻ + H⁺

Basic reaction: HPO₄² + H₂O ⇄ H₂PO₄⁻ + OH⁻

Given Kb > Ka, HPO₄²⁻ has a negligible acidity.

CH₄ cannot release nor accept H⁺ so it has a negligible acidity.

HNO₂ is a weak acid, according to the following reaction:

HNO₂ ⇄ H⁺ + NO₂⁻

7 0

3 years ago

1.Which best explains why ionization energy tends to decrease from the top to the bottom of a group?

tamaranim1 [39]

1.Which best explains why ionization energy tends to decrease from the top to the bottom of a group?

D.Electrons get farther from the nucleus. They experience a weaker attraction to the positive charge of the nucleus.

3.When electrons are removed from the outermost shell of a calcium atom, the atom becomes

D. a cation that has a smaller radius than the atom. Since the atom is losing an electron, it not only becomes positively charged, also the effective nuclear charge diminishes making the remaining electrons aproach the nucleus.

8 0

4 years ago

Read 2 more answers

When 2 moles of Na(s) react with H2O(l) to form NaOH(aq) and H2(g) according to the following equation, 369 kJ of energy are evo

enot [183]

Answer:

Exothermic

q = -8.03 kJ/g

Explanation:

When 2 moles of Na(s) react with H₂O(l) to form NaOH(aq) and H₂(g) according to the following equation, 369 kJ of energy are evolved.

The thermochemical equation is:

2 Na(s) + 2 H₂O(l) → 2 NaOH(aq) + H₂(g) ΔH = -369 kJ

Since the energy is evolved, the reaction is exothermic, which is why the enthalpy of the reaction (ΔH) is negative.

The heat released (q) per gram of Na(s) is (molar mass 22.98 g/mol):

$\frac{-369kJ}{2molNa} .\frac{1molNa}{22.98gNa} =-8.03kJ/g$

4 0

3 years ago

Help Plzz due tomorrow :

hodyreva [135]

D it contains the protons and neutrons

3 0

3 years ago