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wolverine [178]
2 years ago
9

How many silicon atoms are there in 28.09 g of Si?

Chemistry
2 answers:
irinina [24]2 years ago
8 0

Explanation:

28.09 g of silicon contains 6.02×1023 6.02 × 10 23 silicon atoms.

mixer [17]2 years ago
3 0

1 mole = 6.02.10²³ particles (atoms, moleculs, ions)

mole Si = mass : molar mass

mole Si = 28.09 : 28.09 = 1

number of atoms = 1 x 6.02.10²³ = 6.02.10²³ atoms

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6. What is the wavelength (in meters) of the electromagnetic carrier wave transmitted by The Sports
Vsevolod [243]

Answer:

wavelength = 2.81 m

Explanation:

Given that,

The frequency of the Sports  Fan radio station, f = 106.4 MHz

We need to find the wavelength (in meters) of the electromagnetic carrier wave. The relation between frequency and wavelength is given by :

c=f\lambda

Where,

\lambda is wavelength

\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{106.4\times 10^6}\\\\\lambda=2.81\ m

So, the wavelength of the electromagnetic carrier wave is 2.81 m.

8 0
2 years ago
In what ways do scientists not study the history of Earth's climate?
BARSIC [14]
(A) Studying ice cores
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3 years ago
Which two species are most closely related
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3 0
3 years ago
How many milliliters of a 3.4 M NaCl solution would be needed to prepare each solution?
Ksenya-84 [330]

Answer:

a. Approximately 1.3\; \rm mL.

b. Approximately 7.2\; \rm mL.

Explanation:

The unit of concentration "\rm M" is equivalent to "\rm mol \cdot L^{-1}", which means "moles per liter."

However, the volume of both solutions were given in mililiters \rm mL. Convert these volumes to liters:

\displaystyle 45\; \rm mL = 45\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.045\; \rm L.

\displaystyle 330\; \rm mL = 330\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.330\; \rm L.

In a solution of volume V where the concentration of a solute is c, there would be c \cdot V (moles of) formula units of this solute.

Calculate the number of moles of \rm NaCl formula units in each of the two solutions:

Solution in a.:

n = c \cdot V = 0.045\; \rm L \times 0.10\; \rm mol \cdot L^{-1} = 0.0045\; \rm mol.

Solution in b.:

n = c \cdot V = 0.330\; \rm L \times 0.074\; \rm mol \cdot L^{-1} = 0.02442\; \rm mol.

What volume of that 3.4\; \rm M (same as 3.4 \; \rm mol \cdot L^{-1}) \rm NaCl solution would contain that many

For the solution in a.:

\displaystyle V = \frac{n}{c} = \frac{0.0045\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0013\; \rm L.

Convert the unit of that volume to milliliters:

\displaystyle 0.0013\; \rm L = 0.0013\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 1.3\; \rm mL.

Similarly, for the solution in b.:

\displaystyle V = \frac{n}{c} = \frac{0.02442\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0072\; \rm L.

Convert the unit of that volume to milliliters:

\displaystyle 0.0072\; \rm L = 0.0072\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 7.2\; \rm mL.

8 0
3 years ago
Which of these have the same number of particles as 1 mole of water H2O
Fed [463]

Answer:

It is equal to Avogadro's number (NA), namely 6.022 x1023. If we have one mole of water, then we know that it will have a mass of 2 grams (for 2 moles of H atoms) + 16 grams (for one mole O atom) = 18 grams.

Explanation:

The question is not very much clear.

If you are asking for molecules then 1 mole water= 6.023 * 10^23

If you are asking for atoms then 1 mole water= 6.023 * 10^23 * 3

If you are asking for particles then,

So, in your example you would have one mole of water molecules. If you dissociated those water molecules, than you would end up with 2 moles of hydrogen atoms, and one mole of oxygen atoms.

I hope that was helpful!

H=1 proton,1 electron

O=8 protons,8 neutrons and 8 electrons

total particles in one H2O molecule-28

total no. of particles in 1 mole of water- 6.023 * 10^23 * 28

8 0
2 years ago
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