All categories

3 years ago

Calculate the number of moles for 12.044*10^23 number of helium atoms

Chemistry

1 answer:

givi [52]3 years ago

8 0

Answer:

Explanation:

number of moles=number of particle (atoms)/avogadro number (NA)

we know that avogadro number is equal to 6.23*10^23

given number of atoms=12.044*10^23

therefore

moles=12.044*10^23/6.23*10^23=1.9=2

You might be interested in

Calculate the height of a column of liquid benzene (d=0.879g/cm3), in meters, required to exert a pressure of 0.790 atm .

Simora [160]

Here we have to get the height of the column in meter, filled with liquid benzene which exerting pressure of 0.790 atm.

The height of the column will be 0.928 m.

We know the relation between pressure and height of a liquid placed in a column is: pressure (P) = Height (h) × density of the liquid (ρ) × gravitational constant (g).

Here the pressure (P) is 0.790 atm,

or [0.790 × (1.013 × 10⁶)] dyne/cm². [As 1 atm is equivalent to 1.013 × 10⁶ dyne/cm²]

Or, 8.002ₓ10⁵ dyne/cm².

density of benzene is given 0.879 g/cm³.

And gravitational constant (g) is 980 cm/sec².

On plugging the values we get:

8.002×10⁵ = h × 0.879 × 980

Or, h = 928.931 cm

Or, h = 9.28 m (As 1 m = 100 cm)

Thus the height will be 9.28 m.

7 0

3 years ago

Read 2 more answers

How many moles are in 3.4 x 10-7 grams of Silicon dioxide, SiO2?

Varvara68 [4.7K]

Answer:

Number of moles = 0.057 × 10⁻⁷ mol

Explanation:

Given data:

Mass of SiO₂ = 3.4 × 10⁻⁷ g

Number of moles = ?

Solution:

Number of moles = mass/molar mass

Molar mass of SiO₂ = 60 g/mol

by putting values,

Number of moles = 3.4 × 10⁻⁷ g / 60 g/mol

Number of moles = 0.057 × 10⁻⁷ mol

8 0

2 years ago

What is the HONC 1234 rule

kirza4 [7]

The HONC 1234 rule is a way to remember the bonding tendencies of hydrogen, oxygen, nitrogen, and carbon atoms in molecules. Hydrogen tends to form one bond, oxygen two, nitrogen three and carbon four.

8 0

3 years ago

Sodium hydride reacts with excess water to produce aqueous sodium hydroxide and hydrogen gas:NaH (s) H2O (l) → NaOH (aq) H2 (g)A

Anuta_ua [19.1K]

NaH(s)+ H2O (l)=>NaOH(aq)+H2(g)

You want to calculate the mass of NaH, I assume. Otherwise, the question isn't clear. It simply says calculate the mass(??)

So, calculate the moles of H2 gas that satisfy the conditions of 982 ml at 28ºC and 765 torr. But you must subtract the vapor pressure of water at 28º to get the actual pressure of the H2 gas. So, the actual conditions are 982 ml (0.982 L) and 301 K and 765-28 = 737 torr.

PV = nRT

n = PV/RT = (737 torr)(0.982 L)/(62.4 L-torr/Kmol)(301 K)

n = 0.0385 moles H2

moles NaH needed = 0.0385 moles H2 x 1 mole NaH/mole H2 = 0.0385 moles NaH required

mass of NaH needed = 0.0385 moles x 24 g/mole = 0.925 g NaH

Brainliest Please :)

7 0

3 years ago

Read 2 more answers

Acetylene (C2H2), an important fuel in welding, is produced in the laboratory when calcium carbide (CaC2) reacts with water: CaC

Anastaziya [24]

Answer:

There are 1.287 grams of acetylene collected

Explanation:

Total gas pressure = 909 mmHg

Vapor pressure of water = 20.7 mmHg

Pressure of acetylene = 909 mmHg - 20.7 mmHg = 888.3 mmHg

1mmHg = 1 torr

22 ° C + 273.15 = 295.15 Kelvin

Ideal gas law ⇒ pV = nRT

⇒ with p = pressure of the gas in atm

⇒ with V = volume of the gas in L

⇒ with n = amount of substance of gas ( in moles)

⇒ with R = gas constant, equal to the product of the Boltzmann constant and the Avogadro constant (62.36 L * Torr *K^−1 *mol^−1)

⇒ with T = absolute temperature of the gas (in Kelvin)

888.3 torr * 1.024 L = n * 62.36 L * Torr *K^−1 *mol^−1 * 295.15 K

n = 0.04942 moles of C2H2

Mass of C2H2 = 0.04942 moles x 26.04 g/mole = 1.287 g

There are 1.287 grams of acetylene collected

6 0

2 years ago