Which of the following hazards does not apply for methanol?

25 °C = ________ K which one 298 0 33 197

Paraphin [41]

Answer:

298

hope this helps

have a good day :)

Explanation:

5 0

2 years ago

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Write the isotopic symbol for the following (show your work) a) An isotope of iodine whose atoms have 78 neutrons b) An isotope

morpeh [17]

Answer:

For a: The isotopic representation of iodine is $_{53}^{131}\textrm{I}$

For b: The isotopic representation of cesium is $_{55}^{137}\textrm{Cs}$

For c: The isotopic representation of strontium is $_{38}^{52}\textrm{Sr}$

Explanation:

The isotopic representation of an atom is: $_Z^A\textrm{X}$

where,

Z = Atomic number of the atom

A = Mass number of the atom

X = Symbol of the atom

For a:

We are given:

Number of neutrons = 78

Atomic number of iodine = 53 = Number of protons

Mass number = 53 + 78 = 131

Thus, the isotopic representation of iodine is $_{53}^{131}\textrm{I}$

For b:

We are given:

Number of neutrons = 82

Atomic number of cesium = 55 = Number of protons

Mass number = 55 + 82 = 137

Thus, the isotopic representation of cesium is $_{55}^{137}\textrm{Cs}$

For c:

We are given:

Number of neutrons = 52

Atomic number of strontium = 38 = Number of protons

Mass number = 38 + 52 = 90

Thus, the isotopic representation of strontium is $_{38}^{52}\textrm{Sr}$

3 0

2 years ago

Name at least two benefits of using models in science

STatiana [176]

Answer:

Viewing systems from multiple perspectives.

Discovering causes and effects using model tractability.

Improving system understanding through visual analysis.

Explanation:

Got this from google, lol. But, I put three here just in case you could get extra credit for more than two.

3 0

2 years ago

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For the cell constructed from the hydrogen electrode and metal-insoluble salt electrode, B) calculate the mean activity coeffici

Brut [27]

Question:

For the cell constructed from the hydrogen electrode and metal-insoluble salt electrode, B) calculate the mean activity coefficient for 0.124 b HCl solution if E=0.342 V at 298 K

Answer:

The mean activity coefficient for HCl solution is 0.78.

Explanation:

Activity coefficient is defined as the ratio of any chemical activity of any substance with its molar concentration. So in an electrochemical cell, we can write activity coefficient as γ. The equation for determining the mean activity coefficient is

$E=E_{0}-0.0514 \mathrm{V} \ln \gamma$

As we know that $E_{0}$ = 0.22 V and E = 0.342 V, the equation will become

$0.342 V+0.0514 V \ln (0.124)=0.22 V-0.0514 V \ln \gamma$

$0.342 V-0.222 V=-0.0514 V(\ln \gamma+\ln 0.124)$

$0.12 \mathrm{V}=-0.0514 \mathrm{V}(\ln \gamma+\ln 0.124)$

$\frac{0.12}{0.0514}=-\ln (0.124 \gamma)$

$-2.3346=\ln (0.124 \gamma)$

$e^{-2.3346}=0.124 \gamma$

$0.0968=0.124 \gamma$

$\gamma=\frac{0.0968}{0.124}=0.78$

So, the mean activity coefficient is 0.78.

6 0

2 years ago

Determine the electron geometry, molecular geometry and polarity of tecl6.

Delvig [45]

The electron geometry of TeCl6 is octahedral, while the molecular geometry is octahedral, non polar.
Octahedral geometry or six electron pairs is the basic geometry for a molecule containing a central atom with six pairs of electrons, such as TeCl6 or SF6. As we replace bonding pairs with non bonding pairs the molecular geometry changes to square pyramidal to square planar.

3 0

2 years ago