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2 years ago

What is the boiling point of water at standard atmospheric pressure?

Chemistry

1 answer:

denis23 [38]2 years ago

6 0

Answer:100c

Explanation:

water boils at 100c the normal boiling point is the temperature at which the vapour pressure is equal to the standard sea-level atmospheric pressure

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In a classical long run supply model the economy is always doing what

ch4aika [34]

Answer:

Economy is always at the full employment level of output

Explanation:

The economy in a classical long-run supply model will always have the same economic output

8 0

3 years ago

based on the cause and effect relationship between the magnets, which phenomenon is the teacher modeling for her students.

faltersainse [42]

Answer:

Someone breaking up.

Explanation:

8 0

2 years ago

Two methanol-water mixtures are contained in separate tanks. The first mixture contains 40.0 wt% methanol and the second contain

RoseWind [281]

Answer:

$M_{per}= 52.86$

$W_{per}=47.14$

Explanation:

<u>First mixture</u>:

40 wt% methanol - 60 wt% water 200 kg

$m_{met1}=200 kg * 0.4= 80 kg$

$m_{wat1}=200 kg * 0.6= 120 kg$

<u>Second mixture</u>:

70 wt% methanol - 30 wt% water 150 kg

$m_{met2}=150 kg * 0.7= 105 kg$

$m_{wat2}=150 kg * 0.3= 45 kg$

Final mixture:

$m_{metF=80 kg + 105 kg= 185 kg$

$m_{watF}=120 kg + 45 = 165 kg$

$M_{per}=\frac{185 kg}{185 kg + 165 kg}*100= 52.86$

$W_{per}=\frac{165 kg}{185 kg + 165 kg}*100=47.14$

If, the compositions are constant, the only variables are the mass of each mixture used in the final one, so there can be only one independent balance.

8 0

3 years ago

What is the kinetic energy of the emitted electrons when cesium is exposed to UV rays of frequency 1.0×1015Hz?

RideAnS [48]

The kinetic energy of the emitted electrons of cesium when it is exposed to UV rays of frequency $1.0 \times {10^{15}}\;{\text{Hz}}$ is $\boxed{6.63 \times {{10}^{ - 19}}\;{\text{J}}}$

Further Explanation:

Photoelectric effect:

When light is made to fall on any substance, electrons are emitted from it. This is known as the photoelectric effect and the emitted electrons are called photoelectrons. The electrons are emitted because of the transference of energy from light to the electrons.

Cesium is a member of the alkali metal group so it is highly reactive and shows photoelectric effect to the maximum extent. It can remove its electron so easily because of its atomic size. Due to large atomic size of cesium, its outermost electrons are held very less tightly to the nucleus and therefore removed easily.

According to the Planck-Einstein equation, the energy is proportional to the frequency and is expressed as follows:

${\mathbf{E=h\nu }}$ ......(1)

Here,

${\text{E}}$ is the energy.

$h$ is the Plank’s constant.

$\nu$ is the frequency.

The frequency of UV rays is $1.0 \times {10^{15}}\;{\text{Hz}}$ or $1.0 \times {10^{15}}\;{{\text{s}}^{ - 1}}$

The value of Planck’s constant is $6.626 \times {10^{ - 34}}\;{\text{J}}\cdot{\text{s}}$ .

Substitute these values in equation (1)

$\begin{aligned}{\text{E}}&=\left( {6.626 \times {{10}^{ - 34}}\;{\text{J}}\cdot{\text{s}}}\right)\left( {1.0 \times {{10}^{15}}\;{{\text{s}}^{ - 1}}}\right)\\&=6.63\times {10^{ - 19}}\;{\text{J}}\\\end{aligned}$

But when electrons are ejected out from the surface of the substance, all of its energy is considered as kinetic energy.

So the kinetic energy of the electrons is ${\mathbf{6}}{\mathbf{.63 \times 1}}{{\mathbf{0}}^{{\mathbf{ - 19}}}}\;{\mathbf{J}}$ .

Learn more:

1. Statement about subatomic particle: brainly.com/question/3176193

2. The energy of a photon in light: brainly.com/question/7590814

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Structure of the atom

Keywords: kinetic energy, frequency, energy, photoelectric effect, Planck's constant, light, electrons, photoelectrons, proportional, transference, reactive, cesium.

7 0

3 years ago

Read 2 more answers

If the products of a certain reaction are favored (i.e., the ΔG value of the reaction is negative), one would expect a significa

Over [174]

Answer:

positive H and negative S

Explanation:

For a reaction to be spontaneous, the absolute best combination is a negative Delta H and a positive Delta S. When they are both positive, the reaction is only spontaneous at higher temperatures. When they are both negative, the reaction is only spontaneous at lower temperatures. and again if a catalyst is added to the reaction, the activation energy is lowered because a lower-energy transition state is formed. The catalyst does not affect the energy of the reactants or products (and thus does not affect ΔG).

So from these discussions

Ea does not affect G value at all (whether +Ea or -Ea).

And for product to be formed the reaction should be spontaneous, where H is negative and S positive else the reaction will yield low product.

4 0

3 years ago

Read 2 more answers