<span>Answer:
Moles Ca(NO3)2 = 100 x 0.250 / 1000 = 0.025
Ca(NO3)2 >> Ca2+ + 2NO3-
Moles NO3- = 2 x 0.025 = 0.05
Moles HNO3 = 400 x 0.100 / 1000 = 0.04
Total moles = 0.05 + 0.04 = 0.09
Total volume = 500 ml = 0.500 L
M = 0.09 / 0.500 = 0.18</span>
Answer:
0.00001= 1 x 10^-5. Since HCl is an acid, 1 x10^-5 is the H+ concentration. Write only the number of the exponent. Therefore, pH = 5.
<h2>Hello!</h2>
The correct answer is A: Water molecules evaporate and condense at the same rate.
<h2>Why?</h2>
Evaporation is defined as the physical change from liquid to gas, and Condensation is the physical change from gas to liquid.
At any given temperature, these two processes occur at once, in a dynamic equilibrium.
When the lid is closed, evaporation occurs faster than condensation, and pressure increases. Then, when pressure reaches a critical value, condensation starts to occur faster than evaporation, until an equilibrium is reached, and the pressure of the water molecules in the gas phase is maximum for that temperature. The pressure at that point is called Vapor Pressure.
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Answer:
Both Option (I) and Option (III)
Explanation:
Biomass is usually defined as those organic molecules that are obtained from plants and animals, in order to produce energy. It is a renewable resource. Some of the examples of biomass include wood, crop, animal fossil fuel.
A large number of trees are being cut down to construct these biomass energies such as woods. This results in the deforestation process where the forested areas are converted into empty dry soils. This results in the increasing rate of erosion because the prevailing wind and flowing water can easily carry away the topsoil and loses the fertility of the soil.
Thus, the correct answers are both options (I) and (III).
Answer:
Rutherford was the first scientist who proposed the nuclear model of the atom. According to his atomic model, most of the space of an atom is empty, while the nucleus containing protons and neutrons lie at the center of the atom while electrons revolve around nucleus in definite orbits.
If we talk about studies of some other scientists like Dalton, Neil Bohr and JJ Thomson, they all are compatible with Rutherford's results to a large extent.
For example: Dalton's atomic model assumed that atoms of any substance are similar in size and atoms react to form compounds. Rutherford's concept indicated that atoms contain electrons and they are in a specific number which can be shared to form compounds.
If we talk about Bohr's model, it states that electrons revolve around nucleus in specific shells, this again is compatible with Rutherford's results which gave the concept of shells.
If we talk about Thomson's Plum pudding model, that describe atom as negative particles floating within a soup of diffuse positive charge. This is also compatible with the results of Rutherford that state that negative electrons surround positive nucleus.
Rutherford's model was best atomic model but still it took help from many previous studies and therefore was compatible with the results of old models.
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