1. Ba(OH)2 What is the compound

Explain examples of a physical and chemical change of matter

monitta

HEY DEAR..

PHYSICAL CHANGE

Those Changes in which no new substances are formed are called physical changes. it is a temporary changes which can be reversed easily to form the original substance.

Example:- Melting of ice , Making a solution, Glowing of an electric bulb , freezing of water etc.

CHEMICAL CHANGE

Those changes in which new substances are formed are called chemical changes. it means it is permanent changes which are usually irreversible.

Example:- Burning of charcoal, fuels and cutting of trees, even digestion of food is in chemical change.

HOPE ITS HELPFULLL

BE BRAINLY.

6 0

3 years ago

Water flows from the bottom of a large tank where the pressure is 100 psig through a pipe to a turbine which produces 5.82 hp. T

Marianna [84]

Explanation:

Bernoulli equation for the flow between bottom of the tank and pipe exit point is as follows.

$\frac{p_{1}}{\gamma} + \frac{V^{2}_{1}}{2g} + z_{1}$ = $\frac{p_{2}}{\gamma} + \frac{V^{2}_{2}}{2g} + z_{2} + h_{f} + h_{t}$

$\frac{(100 \times 144)}{62.43} + 0 + h[tex] = [tex]\frac{(50 \times 144)}{(62.43)} + \frac{(70)^{2}}{2(32.2)} + 0 + 40 + 60$

h = $\frac{(50 \times 144)}{(62.43)} + \frac{(70)^{2}}{2(32.2)} + 40 + 60 - \frac{(100 \times 144)}{(62.43)}$

= 60.76 ft

Hence, formula to calculate theoretical power produced by the turbine is as follows.

P = mgh

= $100 \times 60.76$

= 6076 lb.ft/s

= 11.047 hp

Efficiency of the turbine will be as follows.

$\eta_{t}$ = $\frac{P_{actual}}{P_{theoretical}}$ × 100%

= $\frac{5.82}{11.047} \times 100%$

= 52.684%

Thus, we can conclude that the efficiency of the turbine is 52.684%.

4 0

3 years ago

Calculate the wavelength of light emitted when each of the following transitions occur in the hydrogen atom. What type of electr

Alecsey [184]

Answer:

The wavelength of the emitted photon will be approximately 655 nm, which corresponds to the visible spectrum.

Explanation:

In order to answer this question, we need to recall Bohr's formula for the energy of each of the orbitals in the hydrogen atom:

$E_{n} = -\frac{m_{e}e^{4}}{2(4\pi\epsilon_{0})^2\hbar^{2}}\frac{1}{n^2} = E_{1}\frac{1}{n^{2}}$ , where:

[tex]m_{e}[tex] = electron mass

e = electron charge

[tex]\epsilon_{0}[tex] = vacuum permittivity

[tex]\hbar[tex] = Planck's constant over 2pi

n = quantum number

[tex]E_{1}[tex] = hydrogen's ground state = -13.6 eV

Therefore, the energy of the emitted photon is given by the difference of the energy in the 3d orbital minus the energy in the 2nd orbital:

[tex]E_{3} - E_{2} = -13.6 eV(\frac{1}{3^{2}} - \frac{1}{2^{2}})=1.89 eV[tex]

Now, knowing the energy of the photon, we can calculate its wavelength using the equation:

[tex]E = \frac{hc}{\lambda}[tex], where:

E = Photon's energy

h = Planck's constant

c = speed of light in vacuum

[tex]\lambda[tex] = wavelength

Solving for [tex]\lambda[tex] and substituting the required values:

[tex]\lambda = \frac{hc}{E} = \frac{1.239 eV\mu m}{1.89 eV}=0.655\mu m = 655 nm[tex], which correspond to the visible spectrum (The visible spectrum includes wavelengths between 400 nm and 750 nm).

5 0

2 years ago

A gas with a volume of 4.0L at a pressure of 205 kPa is allowed to expand to a volume of 12000 mL. What is the pressure in atmos

Leni [432]

Answer: The pressure in atmospheres is 0.674 in the container if the temperature remains constant.

Explanation:

Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.

$P\propto \frac{1}{V}$ (At constant temperature and number of moles)