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2 years ago

Please help i cant find any answers...

Chemistry

2 answers:

Hitman42 [59]2 years ago

8 0

Answer:

98.8

Explanation:

CsF + XeF6 --> CsXeF7

37.8g ................. ?g

37.8g CsF x (1 mol CsF / 151.9g CsF) x (1 mol CsXeF7 / 1 mol CsF) x (397.2g CsXeF7 / 1 mol CsXeF7) = 98.8g CsXeF7 .......... to three significant digits

N76 [4]2 years ago

3 0

Answer:

28.0

Explanation:

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Determine the pH of a 2.8 ×10−4 M solution<br> of Ca(OH)2.

shepuryov [24]

Answer:

pH = 10.75

Explanation:

To solve this problem, we must find the molarity of [OH⁻]. With the molarity we can find the pOH = -log[OH⁻]

Using the equation:

pH = 14 - pOH

We can find the pH of the solution.

The molarity of Ca(OH)₂ is 2.8x10⁻⁴M, as there are 2 moles of OH⁻ in 1 mole of Ca(OH)₂, the molarity of [OH⁻] is 2*2.8x10⁻⁴M = 5.6x10⁻⁴M

pOH is

pOH = -log 5.6x10⁻⁴M

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3 years ago

What happens to the chemical identity of a substance during a physical change?

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Nothing happens because a physical change only changes the appearance of the substance, whereas a chemical change transforms the substance into something completely different.
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3 years ago

A gas balloon has a volume of 106.0 liters when the temperature is 25.0 °C and the pressure is 740.0 mm Hg. What will its volume

ipn [44]

Answer : The final volume of gas will be, 103.3 L

Explanation :

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 740.0 mmHg = 98.4 kPa

Conversion used : (1 mmHg = 0.133 kPa)

$P_2$ = final pressure of gas = 99.3 kPa

$V_1$ = initial volume of gas = 106.0 L

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $25.0^oC=273+25.0=298K$

$T_2$ = final temperature of gas = $20.0^oC=273+20.0=293K$

Now put all the given values in the above equation, we get:

$\frac{98.4kPa\times 106.0L}{298K}=\frac{99.3kPa\times V_2}{293K}$

$V_2=103.3L$

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3 years ago

Describe the modern system of classification. Help please!

DENIUS [597]

Answer:

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Explanation:

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Example:

The scientific name for humans like us is h0m0 sap!ens

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3 years ago

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Describe the movement of electrons when the atom colors by applying ground state and excitement state?

Sladkaya [172]

Answer:

When the excited electron fall back to the lower energy levels the energy is released in the form of radiations.The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum

Explanation:

The electron is jumped into higher level and back into lower level by absorbing and releasing the energy.

The process is called excitation and de-excitation.

Excitation:

When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits. For example if electron jumped from K to L it must absorbed the energy which is equal the energy difference of these two level. The excited electron thus move back to lower energy level which is K by releasing the energy because electron can not stay longer in higher energy level and comes to ground state.

De-excitation:

When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum

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3 years ago