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3 years ago

What are the 4 physical changes you can observe?

2 answers:

8 0

1. ice melting

2. temperature going down at night 

3. water evaporating (like a towel drying out) or water drop on the sink 

4. dew forming on the mirror after a shower

iren2701 [21]3 years ago

6 0

1. ice melting

2. ripping paper

3. dew on mirror because of shower

4. breaking glass

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True.brain is lots of chemical reaction

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3 years ago

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The maximum amount of nickel(II) cyanide that will dissolve in a 0.220 M nickel(II) nitrate solution is...?

sweet [91]

Answer : The maximum amount of nickel(II) cyanide is $5.84\times 10^{-12}M$

Explanation :

The solubility equilibrium reaction will be:

$Ni(CN)_2\rightleftharpoons Ni^{2+}+2CN^-$

Initial conc. 0.220 0

At eqm. (0.220+s) 2s

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ni^{2+}][CN^-]^2$

Now put all the given values in this expression, we get:

$3.0\times 10^{-23}=(0.220+s)\times (2s)^2$

$s=5.84\times 10^{-12}M$

Therefore, the maximum amount of nickel(II) cyanide is $5.84\times 10^{-12}M$

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3 years ago

Calculate the mass of water vapour present in a room of volume 400 m3 that contains air at 27 °C on a day when the relative humi

Alex73 [517]

Answer:

Mass of water = 6251. 706g or 6.25Kg

Explanation:

Relative humidity = (actual vapor pressure/saturation vapor pressure) * 100%

Actual vapor pressure, Pw = relative humidity * saturation vapor pressure

Pw = 60% * (35.6 *0.001)atm = 0.0216atm

Note: 1mbar = 0.001atm

Using the ideal gas equation: PV=nRT; where P = Pw= 0.02136atm, V= (400

* 1000)dm^3, R= 0.082 atmdm^3/kmol, T= (27+273)K, n = number of moles

Note: 1m^3 = 1000dm^3,R is the molar gas constant.

Making n subject of the formula, n = PV/RT

n= (0.02136 * 400000)/(0.082 * 300) = 347.317 moles

Mass (g) = number of moles (n) * molar mass

molar mass of water=18g

Mass of water = 347.317 * 18 = 6251. 706g or 6.25Kg

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3 years ago

Scientists observe patterns in how molecules interact with each other. At the same temperature, for example, liquids have more a

Alla [95]

Answer:

Hello

I am Parth

Can we became friends

and ur intro plz

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2 years ago

Relate what you have learned about the word quantum to the Bohr model.

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3 years ago