1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ki77a [65]
3 years ago
15

What is the mass of 12.3 moles of helium (He)?

Chemistry
1 answer:
anzhelika [568]3 years ago
6 0

Answer : The mass of 12.3 moles of helium (He) is, 49.2 grams.

Solution : Given,

Moles of helium = 12.3 moles

Molar mass of helium = 4 g/mole

Formula used :

\text{Mass of helium}=\text{Moles of helium}\times \text{Molar mass of helium}

\text{Mass of helium}=(12.3mole)\times (4g/mole)=49.2g

Therefore, the mass of 12.3 moles of helium (He) is, 49.2 grams.

You might be interested in
How was nitrogen discovered
Solnce55 [7]
In 1770 a Scottish physician and Chemist Daniel Rutherford performed a simple experiment with which he discovered nitrogen. Rutherford being with an empty bottle that he turned upside down in a pan of water so that the air was trapped. A buring candle was placed inside the bottle with the trapped air causing the water to rise a bit. The part of the air that seemed to "disappear" when the candle was bured was oxygen gas and the part of the air that did not "disappear" Ruthford discovered Nitrogen.
5 0
4 years ago
How is the caloric value of a food sample determined?
bixtya [17]
By multiplying the total amount in grams of a given food sample by energy values established by nutritionists for the particular food type i believe
7 0
3 years ago
Iron and vanadium both have the BCC crystal structure and V forms a substitutional solid solution in Fe for concentrations up to
Bess [88]

Answer:

Explanation:

To find the concentration; let's first compute the average density and the average atomic weight.

For the average density \rho_{avg}; we have:

\rho_{avg} = \dfrac{100}{ \dfrac{C_{Fe} }{\rho_{Fe}} + \dfrac{C_v}{\rho_v} }

The average atomic weight is:

A_{avg} = \dfrac{100}{ \dfrac{C_{Fe} }{A_{Fe}} + \dfrac{C_v}{A_v} }

So; in terms of vanadium, the Concentration of iron is:

C_{Fe} = 100 - C_v

From a unit cell volume V_c

V_c = \dfrac{n A_{avc}}{\rho_{avc} N_A}

where;

N_A = number of Avogadro constant.

SO; replacing V_c with a^3 ; \rho_{avg} with \dfrac{100}{ \dfrac{C_{Fe} }{\rho_{Fe}} + \dfrac{C_v}{\rho_v} } ; A_{avg} with \dfrac{100}{ \dfrac{C_{Fe} }{A_{Fe}} + \dfrac{C_v}{A_v} } and

C_{Fe} with 100-C_v

Then:

a^3 = \dfrac   { n \Big (\dfrac{100}{[(100-C_v)/A_{Fe} ] + [C_v/A_v]} \Big) }    {N_A\Big (\dfrac{100}{[(100-C_v)/\rho_{Fe} ] + [C_v/\rho_v]} \Big)  }

a^3 = \dfrac   { n \Big (\dfrac{100 \times A_{Fe} \times A_v}{[(100-C_v)A_{v} ] + [C_v/A_Fe]} \Big) }    {N_A  \Big (\dfrac{100 \times \rho_{Fe} \times  \rho_v }{[(100-C_v)/\rho_{v} ] + [C_v \rho_{Fe}]} \Big)  }

a^3 = \dfrac   { n \Big (\dfrac{100 \times A_{Fe} \times A_v}{[(100A_{v}-C_vA_{v}) ] + [C_vA_Fe]} \Big) }    {N_A  \Big (\dfrac{100 \times \rho_{Fe} \times  \rho_v }{[(100\rho_{v} - C_v \rho_{v}) ] + [C_v \rho_{Fe}]} \Big)  }

Replacing the values; we have:

(0.289 \times 10^{-7} \ cm)^3 = \dfrac{2 \ atoms/unit \ cell}{6.023 \times 10^{23}} \dfrac{ \dfrac{100 (50.94 \g/mol) (55.84(g/mol)} { 100(50.94 \ g/mol) - C_v(50.94 \ g/mol) + C_v (55.84 \ g/mol)   }   }{ \dfrac{100 (7.84 \ g/cm^3) (6.0 \ g/cm^3 } { 100(6.0 \ g/cm^3) - C_v(6.0 \ g/cm^3) + C_v (7.84 \ g/cm^3)   } }

2.41 \times 10^{-23} = \dfrac{2}{6.023 \times 10^{23} }  \dfrac{ \dfrac{100 *50*55.84}{100*50.94 -50.94 C_v +55.84 C_v} }{\dfrac{100 * 7.84 *6}{600-6C_v +7.84 C_v} }

2.41 \times 10^{-23} (\dfrac{4704}{600+1.84 C_v})=3.2 \times 10^{-24} ( \dfrac{284448.96}{5094 +4.9 C_v})

\mathbf{C_v = 9.1 \ wt\%}

4 0
3 years ago
A sample of hydrogen gas at a pressure of 0.520 atm and a temperature of 26.2°C, occupies a volume of 15.4 liters. If the gas is
Oksanka [162]

Answer:

1.99 atm

Explanation:

Step 1:

Data obtained from the question. This include the following:

Initial pressure (P1) = 0.520 atm

Initial temperature (T1) = 26.2°C

Initial volume (V1) = 15.4L

Final temperature (T2) = constant = 26.2°C

Final volume (V2) = 4.02L

Final pressure (P2) =..?

Step 2:

Determination of the new pressure of the gas.

Since the temperature of the gas is constant, it means the gas is obeying Boyle's law. Thus, the new pressure of the gas can be obtained by applying the Boyle's law equation as shown below:

P1V1 = P2V2

0.520 x 15.4 = P2 x 4.02

Divide both side by 4.02

P2 = (0.520 x 15.4) / 4.02

P2 = 1.99 atm

Therefore, the new pressure of the gas is 1.99 atm

4 0
4 years ago
How are the pressure and temperature of a gas related
expeople1 [14]

Answer:

The pressure of a given amount of gas is directly proportional to its absolute temperature, provided that the volume does not change (Amontons's law). ... The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (Boyle's law).

3 0
3 years ago
Read 2 more answers
Other questions:
  • The steps leading to an algal-bloom fish kill
    14·1 answer
  • Formula<br>gravity<br>of acon due to​
    15·1 answer
  • Theoretically how many moles of carbonic acid will be produced by the 3.00 g sample of NaHCO3
    13·2 answers
  • Which of the following identifies the number and location of protons in a lithium atom
    13·1 answer
  • 1. What is the significance of understanding the characteristics of the earth? essay​
    8·1 answer
  • An element has six valance electrons available for bonding. Which group of the periodic table does this element most likely belo
    5·1 answer
  • Which of the following processes have a ΔS &gt; 0? A. N2(g) + 3 H2(g) → 2 NH3(g) B. Na2CO3(s) + H2O(g) + CO2(g) → 2 NaHCO3(s) C.
    5·1 answer
  • What is the value for ∆Soreaction for the following reaction, given the standard entropy values?
    14·1 answer
  • A solid and a liquid are shaken together in a test tube to produce a milky mixture that eventually separates into a clear liquid
    8·2 answers
  • Examine the scenario.
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!