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2 years ago

Explain why lithium fluoride is a solid at room temperature

1 answer:

8 0

Lithium fluoride is a solid at room temperature because it is a salt that is held together by ionic bonds. Lithium. fluoride has a giant ionic structure.

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Which gas would have the slowest rate of diffusion, assuming that all gases are at the same temperature?

Iteru [2.4K]

Answer: radon (atomic mass 222 amu

Explanation:

To calculate the rate of diffusion of gas, we use Graham's Law.

This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows:

$\text{Rate of diffusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

atomic mass of krypton= 83.8 amu

atomic mass of argon= 39.95 amu

atomic mass of xenon = 131.3 amu

atomic mass of radon= 222 amu

Thus as atomic mass of radon is highest, its rate of diffusion is slowest.

7 0

3 years ago

1. NaOH mass of a solution of 200g in which its percentage is 25%. What mass of sulfuric acid solution is needed to completely n

Ede4ka [16]

Answer:

$m_{H2SO4$ = 61.25 g

$m_{Na2SO4}$ = 88.75 g

Explanation:

$m_{NaOH}$ = $\frac{200 . 25 }{100}$ = 50 g

⇒ $n_{NaOH}$ = $\frac{50}{40}$ = 1.25 (moles)

2NaOH + H2SO4 ⇒ Na2SO4 + 2H2O

2 : 1 : 1 : 2

1.25 (moles)

⇒ $n_{H2SO4}$ = 1.25 × 1 ÷ 2 = 0.625 (moles) ⇒ $m_{H2SO4}$ = 0.625 × 98 = 61.25 g

$n_{Na2SO4}$ = 1.25 × 1 ÷ 2 = 0.625 (moles) ⇒ $m_{Na2SO4}$ = 0.625 × 142 = 88.75 g

4 0

2 years ago

It takes 281.7 kJ of energy to remove 1 mole of electrons from the atoms on the surface of lithium metal. If lithium metal is ir

Alex17521 [72]

Answer:

The maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

Explanation:

We know that total energy

$E = \frac{hc}{\lambda}$ ------------ (1)

Here h = plank's constant = 6.62 × $10^{-34}$ J s

c = speed of light = 3 × $10^{8}$ $\frac{m}{s}$

$\lambda$ = 261 nm = 261 × $10^{-9}$ m

Put all these values in equation (1) we get

E = 7.6 × $10^{-19}$ J

We know that

Total energy = Energy to remove an electron + K.E of electron

Energy to remove an electron = $\frac{281.7 (1000)}{(6.023)10^{23} }$

Energy to remove an electron = 4.67 × $10^{-19}$ J

K.E of electron = Total energy - Energy to remove an electron

K.E of electron = 7.6 × $10^{-19}$ - 4.67 × $10^{-19}$

K.E of electron = 2.93 × $10^{-19}$ Joule

Therefore the maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

3 0

3 years ago

3 points

NNADVOKAT [17]

Answer:

Explanation:

cause

4 0

2 years ago

Which color of light has the greatest energy

ozzi

Answer:

violet

Explanation:

Waves with a short wavelength have the most energy. Red waves have a relatively long wavelength (in the 700 nm range), and violet waves are much shorter - roughly half that. Because violet waves have the shortest wavelength of the visible light spectrum, they carry the most energy (google)

4 0

2 years ago