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3 years ago

Which statement describes the masses of the particles that make up an atom?

1 answer:

6 0

The mass of the atom is equal to the sum of the number of protons and the number of neutrons. In a neutral atom, the number of protons is equal to the number of electrons. The atomic number meanwhile of an atom is equal to the number of protons of the atom.

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The vapor pressure of pure water at 25 °c is 23.8 torr. What is the vapor pressure (torr) of water above a solution prepared by

maxonik [38]

The vapour pressure of the solution is 23.4 torr.

Use Raoult’s Law to calculate the vapour pressure:

p₁ = χ₁p₁°

where

χ₁ = the mole fraction of the solvent

p₁ and p₁° are the vapour pressures of the solution and of the pure solvent

The formula for vapour pressure lowering Δp is

Δp = p₁° - p₁

Δp = p₁° - χ₁p₁° = p₁°(1 – χ₁) = χ₂p₁°

where χ₂ is the mole fraction of the solute.

Step 1. Calculate the mole fraction of glucose

n₂ = 18.0 g glu × (1 moL glu/180.0 g glu) = 0.1000 mol glu

n₁ = 95.0 g H_2O × (1 mol H_2O/18.02 g H_2O) = 5.272 mol H_2O

χ₂ = n₂/(n₁ + n₂) = 0.1000/(0.1000 + 5.272) = 0.1000/5.372 = 0.018 62

Step 2. Calculate the vapour pressure lowering

Δp = χ₂p₁° = 0.018 62 × 23.8 torr = 0.4430 torr

Step 3. Calculate the vapour pressure

p₁ = p₁° - Δp = 23.8 torr – 0.4430 torr = 23.4 torr

3 0

3 years ago

Why do covalent compounds tend to have lower melting points than ionic compounds?

vitfil [10]

Because ionic compounds' strong bonds form network structures, which have a stronger attraction than the covalent compounds which are molecules.

6 0

3 years ago

Read 2 more answers

Someone please help me ASAP!

stealth61 [152]

Answer:

Increasing the temperature of the reactants

Explanation:

This causes more vibrations to occur, hence increasing the kinetic energy of the particles. The number of particles with activation energy would increase as well because they have higher kinetic energy. Kinetic energy is also the reason why the collision between particles increases. And the frequency of effective collisions increases because of the kinetic energy as well, keep in mind the particles must also be orientated in the correct way as well.

3 0

3 years ago

I’LL MAKE YOU BRAINLIEST+ FREE POINTS

Pavel [41]

Answer:

The solution's new volume is 1.68 L

Explanation:

Dilution is the procedure to prepare a less concentrated solution from a more concentrated one, and simply consists of adding more solvent. So, in a dilution the amount of solute does not vary, but the volume of the solvent varies.

In summary, a dilution is a lower concentration solution than the original.

The way to do the calculations in a dilution is through the expression:

Ci*Vi=Cf*Vf

where C and V are concentration and volume, respectively; and the i and f subscripts indicate initial and final respectively.

In this case, being:

Ci= 7 M
Vi= 0.60 L
Cf= 2.5 M
Vf=?

Replacing:

7 M*0.60 L= 2.5 M* Vf

Solving:

$Vf=\frac{7 M*0.60 L}{2.5 M}$

Vf= 1.68 L

The solution's new volume is 1.68 L

4 0

3 years ago

What contains more hydrogen atoms, 1.0 mole of H20 or 1.0 moles of НЗО?

Vladimir [108]

A mole of an element refers to 6.02e23 atoms so they would have the same amount of atoms

4 0

3 years ago