A ___________________________ is a mixture in which the properties of thesubstances are spread evenly.

Lapatulllka [165]

the answer is true the first one

3 0

2 years ago

What is the mean free path for the molecules in an ideal gas when the pressure is 100 kPa and the temperature is 300 K given tha

sladkih [1.3K]

Answer:

The mean free path = 2.16*10^-6 m

Explanation:

Given:

Pressure of gas P = 100 kPa

Temperature T = 300 K

collision cross section, σ = 2.0*10^-20 m2

Boltzmann constant, k = 1.38*10^-23 J/K

To determine:

The mean free path, λ

Calculation:

The mean free path is related to the collision cross section by the following equation:

$\lambda =\frac{1}{n\sigma }------(1)$

where n = number density

$n = \frac{P}{kT}-----(2)$

Substituting for P, k and T in equation (2) gives:

$n = \frac{100,000 Pa}{1.38*10^{-23} J/K*300K} =2.42*10^{25}\ m^{3}$

Next, substituting for n and σ in equation (1) gives:

$\lambda =\frac{1}{2.42*10^{25}m^{-3}* .0*10^{-20}m^{2}}=2.1*10^{-6}m$

6 0

2 years ago

Energy is conserved in chemical reactions. It is neither created nor_____

aivan3 [116]

Answer:

destroyed, from, endothermic

Explanation:

Energy is conserved in chemical reactions. It is neither created nor destroyed but can be transferred from one form to another.

An exothermic reaction transfers energy from the reacting substance to the surroundings. The body of the container feels warm. An exothermic reaction has a negative value of enthalpy.

An endothermic reaction transfers energy from the surroundings to the reacting substance. The body of the container feels cold. In an endothermic reaction, enthalpy is positive.

6 0

2 years ago

How many electrons does the isotope helium-5 have

baherus [9]

Answer:

two electrons.

Explanation:

Helium-5, like all other helium isotopes, has two protons and two electrons. Its different from the others in the fact that it has three neutrons. It is one of the unstable isotopes, having a half-life of significantly less than a picosecond (a trillionth of a second). your welcome!!

6 0

2 years ago

A solution at 25 ∘C has pOH = 10.53. Which of the following statements is or are true? The solution is acidic. The pH of the sol

Lady bird [3.3K]

Answer:

The true statements are:

The solution is acidic

The pH of the solution is 14.00 - 10.53.

$10^{-10.53}=[OH^-]$

Explanation:

The pH of the solution is defined as negative logarithm of hydrogen ion concentration present in the solution .

$pH=-\log[H^+]$

The pH value more 7 means that hydrogen ion concentration is less ,alkaline will be the solution.
The pH value less 7 means that hydrogen ion concentration is more ,acidic will be the solution.
The pH value equal to 7 indicates that the solution is neutral.

The pOH of the solution is defined as negative logarithm of hydroxide ion concentration present in the solution .

$pOH=-\log[OH^-]$