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3 years ago

1. Why does light have different effects on various materials?

Chemistry

2 answers:

IRINA_888 [86]3 years ago

5 0

Answer:

this kenny why u cheating on brainly?

Explanation:

Debora [2.8K]3 years ago

4 0

Light basically evaporates pigments such as colored paper. Exposed pigment fading is kind of like getting colored paper wet. It will fade and bleed.

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6.02 kJ>mol. When a small ice cube at -10°C is put into a cup of water at room temperature, which of the following plays a gr

9966 [12]

Answer:

Heat transfer during melting of ice plays greater role in cooling of liquid water.

Explanation:

Temperature of ice = -10 °c

Temperature of water = 0 °c

When ice cube is dipped in to the water.the heat transfer

Q = m c ΔT

⇒ Q = 1 × 2.01 × 10

⇒ Q = 20.1 KJ

Heat transfer during melting of ice $Q_{melt}$ = latent heat of ice

Latent heat of ice = 334 KJ

⇒ $Q_{melt}$ = 334 KJ

Heat transfer during melting of ice is greater value than heat transfer during warming of ice from -10°C to 0°C.

Thus heat transfer during melting of ice plays greater role in cooling of liquid water.

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3 years ago

Research benzene and list two modern-day commercial uses for his chemical

Juli2301 [7.4K]

Benzene is used for pesticides and detergents. It is also used for other things besides these.

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3 years ago

Why do different molecules require different masses to make 1 mol

Wewaii [24]

Answer:

Different substances have different molecular masses. Thus, equal masses have different numbers of atoms, molecules, or moles. On the other hand, equal numbers of moles of different substances have different masses.

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3 years ago

How long, in seconds, would it take for the concentration of A to decrease from 0.860 M to 0.310 M?

kogti [31]

Answer:

2.038 seconds.

Explanation:

So, in the question above we are given the following parameters in order to solve this question. We are given a rate constant of 0.500 s^-, initial concentration= 0.860 M and final concentration= 0.310 M,the time,t =??.

Assuming that the equation for the first order of reaction is given below,that is;

A ---------------------------------> products.

Recall the formula below;

B= B° e^-kt.

Therefore, e^-kt = B/B°.

-kt = ln B/B°.

kt= ln B°/B.

Where B° and B are the amount of the initial concentration and the amount of the concentration remaining, k is the rate constant and t = time taken for the concentration to decrease.

So, we have; time taken,t = ln( 0.860/.310)/0.500.

==> ln 2.77/0.500.

==> time taken,t =2.038 seconds.

6 0

3 years ago

How many hours does it take to form 15.0 L of O₂ measured at 750 torr and 30°C from water by passing 3.55 A of current through a

rosijanka [135]

Answer:

The correct answer is 17.845 hours.

Explanation:

To solve the question, that is, to determine the hours required there is a need to combine the Faraday's law of electrolysis with the Ideal gas law.

Based on Faraday's law, m = Mit/nF

Here m is the mass in grams, M is the molecular mass, i is the current in amperes, t is time, n is the number of moles of electron per mole of oxygen formed and F is the Faraday's constant (the value of F is 96487 coulombs/mole).

From the above mentioned equation,

t = mnF/Mi ------(i)

Now based on ideal gas law's, PV = nRT or PV = m/M RT, here n = mass/molecular mass.

So, from the above gas law's equation, m = PVM/RT

Now putting the values of m in the equation (i) we get,

t = PVMnF/MiRT = PVnF/iRT

Based on the given information, the value of P is 750 torr or 750/760 atm = 0.98 atm, the value of v is 15.0 L, T is 30 degree C or 273 + 30 K = 303 K, i is 3.55 Amperes, and the value of R is 0.0821 atm L/mol K.

1 mole of oxygen gives 2 moles of electrons, therefore, 2 moles of oxygen will give 4 moles of electrons.

Now putting the values we get,

t = PVnF/iRT

= 0.98 atm × 15.0 L × 4 moles of electron × 96487 coulombs per mole / 3.55 coulomb per sec × 0.0821 atm L per mole-K × 303 K

= 64243.81 secs or 64243.81/3600 hr

= 17.845 hours

7 0

3 years ago