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4 years ago

List two things that do not change between isotopes of an element

Chemistry

2 answers:

sergij07 [2.7K]4 years ago

8 0

Answer:

Because different isotopes have different numbers of neutrons, they do not all weigh the same or have the same mass. Different isotopes of the same element have the same atomic number. They have the same number of protons. The atomic number is decided by the number of protons.

Lady bird [3.3K]4 years ago

5 0

Answer:

Explanation:

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In at least 4 complete sentences, describe the similarities and differences between Avogadro's Law and Charles' Law.

viktelen [127]

answer

Avogadro's law states that, at constant temperature and pressure, the volume of a gas is directly proportional to the number of moles present. In other words, equal volumes of gases at the same pressure and temperature contain the same number of molecules - this is true regardless of their physical properties or chemical nature.

This number of molecules is

6.022

⋅

and is known as Avogadro's number,

Matematically, Avogadro's law can be written like this

, or, better yet,

Avogadro's law, as well as Boyle's law and Charles' law, are special cases of the ideal gas law,

. If temperature and pressure are kept constant, and knowing that

is of course constant, then

→

, which represents Avogadro's law.

The ideal gas law can also be written to incorporate

, since the number of moles are actually the number of molecules divided by Avogadro's number

⋅

, where

represents the number of molecules.

7 0

3 years ago

Two perfumes are released at the same time. If one is standing 7.5 m from the point of release. Perfume A (molar mass 275 g/mol)

natta225 [31]

According to Graham's Law of Diffusion," Diffusion of Gas is inversely proportional to square root of its Molecular Mass or Density".

rᵇ/rᵃ =   $\sqrt{da/db}$
Or,
  rᵇ/rᵃ =   $\sqrt{Ma/Mb}$ ----- (1)
As,
Ma = 275 g/mol

Mb = 205 g/mol

Putting Values in eq.1,

rᵇ/rᵃ =   $\sqrt{275/205}$

rᵇ/rᵃ = 1.15

Result:
Perfume B will diffuse 1.15 times faster than Perfume A. Hence, Perfume B will be first smelled by the person.

6 0

3 years ago

A particle that orbits the nucleus in an atom is called a(n)

MrMuchimi

Answer:

The correct answer is electrons.

Explanation:

The electrons refer to the negatively charged constituents, which are arranged in the orbits around the nucleus of an atom. It determines all the chemical and physical characteristics of an atom except the radioactivity and mass. It is a stable subatomic particle witnessed in all the atoms and functioning as the chief carrier of electricity in solids.

5 0

3 years ago

Read 2 more answers

Find the pH of the equivalence point and the volume (mL) of 0.0372 M NaOH needed to reach the equivalence point in the titration

elixir [45]

Answer:

8.54

Explanation:

At equivalence point :

42.2 X 0.052 = Vol. NaOH X 0.0372

Vol of NaOH = 2.1944/0.0372 = 58.99 ml

So volume of NaOH recquired to reach equivalence point = 58.99 ml

Number of miliimoles of CH3COOH = molarity X volume in ml = 42.2 X 0.052 = 2.1944 millimoles

Number of millimoles of NaOH = 58.99 X 0.0372 = 2.1944

Now CH₃COOH and NaOH reacts to give CH₃COONa according to the reaction :

CH₃COOH + NaOH ------> CH₃COONa + H₂O

1 mole of CH₃COOH reacts with 1 mole of NaOH to give 1 mole of CH₃COONa

So 2.1944 millimoles of CH₃COOH will react with 2.1944 millimoles of NaOH to give 2.1944 millimoles of CH₃COONa

So all the acid (CH₃COOH) and base (NaOH) has been converted into salt (CH₃COONa) so there is no acid or base left.

Now molarity of CH₃COONa = number of millimoles of CH₃COONa/total volume in ml = 2.1944/(58.99 + 42.2) = 2.1944/101.19 = 0.02169 M

So using the hydrolysis equation :

pH = 1/2 [ pKw + pKa + log c ]

Ka for acetic acid = 1.75 X 10⁻⁵

so pKa = -log (1.75 X 10⁻⁵) = 4.74

Kw = 10⁻¹⁴

so pKw = -log 10⁻¹⁴ = 14

c = 0.02169

so log c = log 0.02169 = -1.66

putting the values....

pH = 1/2 [14 + 4.74 - 1.66 ]

pH = 1/2 [ 17.08] = 8.54

6 0

3 years ago

Read 2 more answers

2.0 L of a gas is at STP. What is the new pressure in kPa if the volume changes to 10.5 L and the temperature and # of molecules

Alexandra [31]

Answer:

What is the new volume if the temperature is constant? V=2.50L. P = lookPa. P2=40k Pa. V2 = x. PV = P2 ... If a sample of gas occupies 6.8 L at 327°C

5 0

3 years ago