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3 years ago

The atomic mass of an element is found by which of the following methods?

1 answer:

8 0

On the periodic table it is the number on the bottom of the element.
<span>If you know the amount of neutrons you can add it to the number of protons to find the atomic mass NUMBER, which is a good approximate of the atomic mass. </span>

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A gas has a volume of 56.3L when its temperature is 280 K. What will volume be at 220K?

Alex Ar [27]

Answer:

44.23 L

use pascal's formula

8 0

3 years ago

g For the reaction Ag2S(s)⇌2Ag+(aq)+S2−(aq)Ag2S(s)⇌2Ag+(aq)+S2−(aq), Keq=2.4×10−4Keq=2.4×10−4, and the equilibrium concentration

Roman55 [17]

Answer:

0.32 M

Explanation:

Step 1: Write the balanced reaction at equilibrium

Ag₂S(s) ⇌ 2 Ag⁺(aq) + S²⁻(aq)

Step 2: Calculate the concentration of Ag⁺ at equilibrium

We will use the formula for the concentration equilibrium constant (Keq), which is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients. It only includes gases and aqueous species.

Keq = [Ag⁺]² × [S²⁻]

[Ag⁺] = √{Keq / [S²⁻]}

[Ag⁺] = √{2.4 × 10⁻⁴ / 0.0023} = 0.32 M

8 0

3 years ago

Which of the following metals (M) will form an ionic compound with nitrogen with the general formula M3N2? Hint: Think about how

Basile [38]

Answer:

See explanation

Explanation:

The question is incomplete but i will try to give you all the necessary guide that you need in order to answer the question.

When compounds are formed, atoms exchange valency. The valency of nitrogen is three while that of the metal is two. The exchange yields M3N2.

If the compound has been specifically mentioned to be a metal, then it must be a group two element. It could be any of Mg, Ca, Sr, Ba or Ra. I did not mention Be here because most of its compounds are covalent.

This will help you to answer the complete question.

5 0

3 years ago

Read 2 more answers

Mercury and its compounds have uses from fillings for teeth (as a mixture with silver, copper, and tin) to the production of chl

Y_Kistochka [10]

Answer:

0.6410g of HgS (mercury (II) sulfide) are formed

Explanation:

First you should write the balanced chemical equation, so we have:

$Na_{2}S+Hg(NO_{3})_{2}=HgS+_{2}NaNO_{3}$

Where:

$Na_{2}S$ is the formula for the sodium sulfide

$Hg(NO_{3})_{2}$ is the formula for the mercury (II) nitrate

$HgS$ is the formula for the mercury (II) sulfide

and

$NaNO_{3}$ is the formula for the sodium nitrate

Then you should calculate the amount of each substance in each solution, so:

- For the $Na_{2}S$ :

$Molarity=\frac{n_{Na_{2}S}}{Lofsolution}$

$n_{Na_{2}S}=0.048M*0.236L$

$n_{Na_{2}S}=0.010856$ moles of $Na_{2}S$

- For the $Hg(NO_{3})_{2}$ :

$Molarity=\frac{n_{Hg(NO_{3})_{2}}}{Lofsolution}$

$n_{Hg(NO_{3})_{2}}=0.019M*0.145L$

$n_{Hg(NO_{3})_{2}}=0.002755$ moles of $Na_{2}S$

As the quantity of $Hg(NO_{3})_{2}$ is smaller than the quantity of $Na_{2}S$ . The $Hg(NO_{3})_{2}$ is the limiting reagent and you should work with this quantity, so we have:

$0.002755molesHg(NO_{3})_{2}*\frac{1molHgS}{1molHg(NO_{3})_{2}}=0.002755$ moles of HgS

And as the molar mass of the HgS is $232.66\frac{g}{mol}$ you can calculate the mass of HgS that is produced:

$0.002755molesHgS*\frac{232.66gHgS}{1molHgS}=0.6410g$ HgS

3 0

3 years ago

A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is

RUDIKE [14]

Answer:

523°C

Explanation:

Step 1:

Data obtained from the question.

Diameter (d) = 31.0 cm

Height (h) = 37.2 cm

Pressure (P) = 5.90 MPa

Mass of ClF5 = 3.27 kg

Temperature (T) =?

Step 2:

Determination of the volume of the stainless-steel cylinder.

Volume of cylinder = πr^2h = π/4d^2h

V = π/4 x (31)^2 x 37.2

V = 28077.36 cm3

Converting the volume to L, we have:

1 cm3 = 0.001 L

Therefore, 28077.36 cm3 = 28077.36 x 0.001 = 28.07736 L

Step 3:

Conversion of 5.90 MPa to atm.

1 MPa = 9.869 atm

Therefore, 5.90 MPa = 5.90 x 9.869

= 58.2271 atm

Step 4:

Determination of the number of mole of chiorine pentafluoride gas (ClF5). This is illustrated below:

Molar Mass of ClF5 = 35.5 + (19x5) = 35.5 + 95 = 130.5g/mol

Mass of ClF5 = 3.27kg =3.27x10000

Mass of ClF5 = 3270g

Number of mole = Mass /Molar Mass

Number of mole of ClF5 = 3270/130.5

Number of mole of ClF5 = 25.057 moles

Step 5:

Determination of the temperature.

Applying the ideal gas equation

PV = nRT, the temperature T, can be obtained as follow:

P = 58.2271 atm

V = 28.07736 L

n = 25.057 moles

R (gas constant) = 0.082atm.L/Kmol

T=?

PV = nRT

Divide both side by nR

T = PV /nR

T = (58.2271x28.07736)/(25.057x0.082)

T = 795.68 K

Step 6:

Conversion of Kelvin temperature to celsius temperature.

°C = K - 273

K = 795.68 K

°C = 795.68 - 273

°C = 523°C

Therefore, the maximum safe operating temperature the engineer should recommend is 523°C

5 0

3 years ago