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Svetllana [295]
3 years ago
11

Sunspots appear dark because they are what ?

Chemistry
1 answer:
dsp733 years ago
3 0
Sunspots have strong magnetic fields, thus being much cooler than their surroundings. Yet, they are still individually very hot and can reach up to a temp of 3,800 K. But since they are cooler than their surroundings, they appear to be much darker to the visible eye. 

Let me know if you need anything further. :)

                             - Dotz
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Titanium and chlorine react to form titanium(IV) chloride, like this:
leva [86]

Answer:

the value of equilibrium constant for the reaction is 8.5 * 10⁷

Explanation:

Ti(s) + 2 Cl₂(g) ⇄ TiCl₄(l)

equilibrium constant Kc = \frac{1}{[Cl_2]^2}

Given that,

We are given:

Equilibrium amount of titanium = 2.93 g

Equilibrium amount of titanium tetrachloride = 2.02 g

Equilibrium amount of chlorine gas = 1.67 g

We calculate the No of mole = mass / molar mass

mass of chlorine gas = 1.67 g

Molar mass of chlorine gas = 71 g/mol

mole of chlorine = 1.67 / 71

= 7.0L

Concentration of chlorine is = no of mole / volume

= 0.024 / 7

= 3.43 * 10⁻³M

equilibrium constant Kc  = \frac{1}{[Cl_2]^2}

= \frac{1}{[3.43 * 10^-^3]^2}

= 8.5 * 10⁷

4 0
3 years ago
What is the mass of the block of iron illustrated below?
Mandarinka [93]
VOLUME= 5cm*10cm*2cm =100cm^3
but density of iron=7.874g/cm^3
mass=7.874g*100 =787.4g
mass of that block = 787.4g
7 0
3 years ago
Read 2 more answers
If the molar absorptivity constant for the red dye solution is 5.56×104 M-1cm-1, calculate the molarity of the red dye solution
Shtirlitz [24]

Explanation:

a) Using Beer-Lambert's law :

Formula used :

A=\epsilon \times c\times l

where,

A = absorbance of solution = 0.945

c = concentration of solution = ?

l = length of the cell = 1.20 cm

\epsilon = molar absorptivity of this solution =5.56\times 10^4 M^{-1} cm^{-1}

0.945=5.56\times 10^4 M^{-1} cm^{-1}\times 1.20 \times c

c=1.4163\times 10^{-5} M=14.16 \mu M

(1\mu M=10^{-6} M)

14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.

b) c=1.4163\times 10^{-5} mol/L

1 L of solution contains 1.4163\times 10^{-5} moles of red dye.

Mass of 1.4163\times 10^{-5} moles of red dye:

1.4163\times 10^{-5}\times 879.86g/mol=0.01246 g

(w/v)\%=\frac{\text{Mass of solute (g)}}{\text{Volume of solvent (mL)}}\times 100

red(w/v)\%=\frac{0.01246 g}{1000 mL}\times 100=0.001246\%

c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.

Concentration of red dye solution = c=1.4163\times 10^{-5} M

Concentration of red solution after dilution = c'

c=c'\times 5

1.4163\times 10^{-5} M=c'\times 5

c'=2.83\times 10^{-6} M

The final concentration of the diluted solution is 2.83\times 10^{-6} M

8 0
3 years ago
PLEASE HELP ASAP!!!!
Kruka [31]
The answer is A! Heat energy is thermal energy. To remember all Energy use M.E.L.T.S!

M- Mechanical energy
E- Electrical energy
L- Light energy
T- Thermal energy
S- Sound energy
8 0
3 years ago
Read 2 more answers
Which statement is true about molarity and percent by mass? (3 points)
lakkis [162]

Answer:  The correct option is, They are different units of concentration.

Explanation: Molarity : It is defined as the number of moles of solute present in one liter of solution.

5 0
3 years ago
Read 2 more answers
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