Ask question

Ask question

All categories

3 years ago

11

A flask containing neon gas is connected to an open-endedmercury manometer. The open end is exposed to the atmosphere, wherethe

prevailing pressure is 745 torr. The mercury level in the openarm is 50 mm below that in the arm connected to the flask of neon.What is the neon pressure, in torr?
A. -50 torr

B. 50 torr

C. 695 torr

D. 795 torr

E. None of these choices is correct.

1 answer:

Tasya [4]3 years ago

5 0

Answer: Option (C) is the correct answer.

Explanation:

The given data is as follows.

$P_{bar}$ = 745 torr

$\Delta P$ = - 50 (the value is negative because on the open side its level is lower than the side connected to the gas)

Now, formula to calculate the pressure of neon gas will be as follows.

$P_{neon} = P_{bar} + \Delta P$

Putting the given values into the above formula as follows.

$P_{neon} = P_{bar} + \Delta P$

= $745 torr + (- 50 torr)$

= 695 torr

Thus, we can conclude that the neon pressure is 695 torr.

You might be interested in

The human body can get energy by metabolizing proteins, carbohydrates or fatty acids, depending on the circumstances. Roughly sp

Kamila [148]

Answer:

the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose is 1.0111

Explanation:

Given the data in the question;

To determine the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose, first we get the molar masses of both alanine and glucose

we know that;

Molar mass of alanine ( C₃H₇NO₂ ) = 89.09 g/mol

Molar mass of glucose ( C₆H₁₂O₆ ) = 180.16 g/mol

now, { metabolizing each gram }

moles of alanine = mass taken / molar mass

= 1g / 89.09 g/mol = 1/89.09 moles

moles of glucose = mass taken / molar mass

= 1g / 180.16 g/mol = 1/180.16 moles

In each molecule of alanine, we have 3 atoms of carbon.

Also, in each molecules of glucose, we have 6 atoms of carbon

so,

number of moles of Carbons in alanine = 3 × 1/89.09 moles = 0.03367

number of moles of Carbons in glucose = 6 × 1/180.16 moles = 0.0333

so ratio of energy will be the ratio of carbon atoms, which is;

⇒ 0.03367 / 0.0333 = 1.0111

Therefore, the ratio of the energy the body gets metabolizing each gram of alanine to the energy the body gets metabolizing each gram of glucose is 1.0111

7 0

3 years ago

After 11.5 days, 12.5% of a sample of radon-222 that originally weighed 42g remains. What is the half-life of this isotope?

Bond [772]

Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value. The equation to describe the decay is
Nt=N0(1/2) $^{t/t(1/2)}$ where N0 is the initial quantity, Nt is the remaining quantity after time t, t1/2 is the half-time. So work out the equation, t1/2 = t (-ln2)/ln(Nt/N0) = 11.5*(-ln2)/ln(12.5/100) = 3.83 days

5 0

3 years ago

Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic

Kisachek [45]

Answer:

A) 10.75 is the concentration of arsenic in the sample in parts per billion .

B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C) It will take 1.37 years to remove all of the arsenic from the lake.

Explanation:

A) Mass of arsenic in lake water sample = 164.5 ng

The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.

To calculate the ppm of oxygen in sea water, we use the equation:

$\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9$

Both the masses are in grams.

We are given:

Mass of arsenic = 164.5 ng = $164.5\times 10^{-9} g$

$1 ng=10^{-9} g$

Volume of the sample = V = $15.3 cm^3$

Density of the lake water sample ,d= $1.00 g/cm^3$

Mass of sample = M = $d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g$

$ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75$

10.75 is the concentration of arsenic in the sample in parts per billion.

B)

Mass of arsenic in $1 cm^3$ of lake water = $\frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g$

Mass of arsenic in $0.710 km^3$ lake water be m.

$1 km^3=10^{15} cm^3$

Mass of arsenic in $0.710\times 10^{15} cm^3$ lake water :

$m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g$

1 g = 0.001 kg

7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg

7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C)

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

$\frac{2.74}{41.90} days$

Then days required to remove 7,633.66 kg of arsenic from the lake water :

$=7,633.66\times \frac{2.74}{41.90} days=499.19 days$

1 year = 365 days

499.19 days = $\frac{499.19}{365} years = 1.367 years\approx 1.37 years$

It will take 1.37 years to remove all of the arsenic from the lake.

3 0

3 years ago

Which of these half-reactions represents reduction?

gogolik [260]

Answer: The half-reactions represents reduction are as follows.

$Cr_{2}O^{2-}_{7} \rightarrow Cr^{3+}$
$MnO^{-}_{4} \rightarrow Mn^{2+}$

Explanation:

A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element takes place is called reduction-half reaction.

For example, the oxidation state of Cr in $Cr_{2}O^{2-}_{7}$ is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.

$Cr_{2}O^{2-}_{7} + 3 e^{-} \rightarrow Cr^{3+}$

Similarly, oxidation state of Mn in $MnO^{-}_{4}$ is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.

$MnO^{2-}_{4} + 5 e^{-} \rightarrow Mn^{2+}$

Thus, we can conclude that half-reactions represents reduction are as follows.

$Cr_{2}O^{2-}_{7} \rightarrow Cr^{3+}$
$MnO^{-}_{4} \rightarrow Mn^{2+}$

3 0

3 years ago

You have three elements, A, B, and C, with the following electronegativity values:

DerKrebs [107]

#AB

Electronegativity difference=3.3-2.9=0.4.

It's a covalent bond.
Gaseous or solid substance.

#AC

Electronegativity difference=3.3-0.7=2.6

Its an ionic bond.
Solid substance.

#BC

Electronegativity difference=2.9-0.7=2.3

It's an ionic bond
Solid substance

6 0

3 years ago