Answer:
Colloids
There are two basic methods of forming a colloid: reduction of larger particles to colloidal size, and condensation of smaller particles (e.g., molecules) into colloidal particles. Some substances (e.g., gelatin or glue) are easily dispersed (in the proper solvent) to form a colloid; this spontaneous dispersion is called peptization. A metal can be dispersed by evaporating it in an electric arc; if the electrodes are immersed in water, colloidal particles of the metal form as the metal vapor cools. A solid (e.g., paint pigment) can be reduced to colloidal particles in a colloid mill, a mechanical device that uses a shearing force to break apart the larger particles. An emulsion is often prepared by homogenization, usually with the addition of an emulsifying agent. The above methods involve breaking down a larger substance into colloidal particles. Condensation of smaller particles to form a colloid usually involves chemical reactions—typically displacement, hydrolysis, or oxidation and reduction.
A. 8 mol
B. 2 mol
C. 6 mol
D. 4 mol
Answer:
The amswer would be A due to the ratio between ethane and carbon dioxide being 1:2. Due to this, you double the moles that are reacting
Answer:
sorry I don't know
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Answer:
K.E. = 5.4362 × 10⁻¹⁹ J
Explanation:
The expression for Bohr velocity is:
Applying values for hydrogen atom,
Z = 1
Mass of the electron () is 9.1093×10⁻³¹ kg
Charge of electron (e) is 1.60217662 × 10⁻¹⁹ C
= 8.854×10⁻¹² C² N⁻¹ m⁻²
h is Plank's constant having value = 6.626×10⁻³⁴ m² kg / s
We get that:
Given, n = 2
So,
Kinetic energy is:
So,
K.E. = 5.4362 × 10⁻¹⁹ J
Answer:
Average atomic mass = 19.9 amu
Explanation:
Isotopes can be defined as two or more forms of a chemical element that are made up of equal numbers of protons and electrons but different numbers of neutrons.
Generally, the isotopes of a chemical element have the same chemical properties because of their atomic number but different physical properties due to their atomic weight (mass number).
Given the following data;
Relative abundance of Z-19 = 55%
Relative abundance of Z-21 = 45%
Atomic mass of Z-19 = 19 amu
Atomic mass of Z-21 = 21 amu
To find the average atomic mass;
Average atomic mass = 19 * (55/100) + 21 * (45/100)
Average atomic mass = 19*0.55 + 21*0.45
Average atomic mass = 10.45 + 9.45
Average atomic mass = 19.9 amu
Therefore, the average atomic mass for element Z is 19.9 amu.
2) 2.01 mol N2O
Answer :
Part 1: 4.93 moles of contains 9.86 moles of oxygen atoms.
Part 2: 2.01 moles of contains 2.01 moles of oxygen atoms.
Explanation :
Part 1: 4.93 mol
In 1 mole of , there are 2 atoms of hydrogen and 2 atoms of oxygen.
As, 1 mole of contains 2 moles of oxygen atoms.
So, 4.93 moles of contains moles of oxygen atoms.
Thus, 4.93 moles of contains 9.86 moles of oxygen atoms.
Part 2: 2.01 mol
In 1 mole of , there are 2 atoms of nitrogen and 1 atom of oxygen.
As, 1 mole of contains 1 mole of oxygen atoms.
So, 2.01 moles of contains moles of oxygen atoms.
Thus, 2.01 moles of contains 2.01 moles of oxygen atoms.
Most of the fresh water on Earth is groundwater.
About 75 percent of the fresh water on Earth is frozen in ice sheets.
The largest source of usable fresh water is groundwater.
More fresh water is in the atmosphere than in rivers and lakes.
Answer: A., C., and D.
Explanation: On Edge!!
I will keep all the true statements bold, so you can understand that those are true.
Answer:
Only about 3 percent of Earth's water is fresh water.
Most of the fresh water on Earth is groundwater.
About 75 percent of the fresh water on Earth is frozen in ice sheets.
The largest source of usable fresh water is groundwater.
More fresh water is in the atmosphere than in rivers and lakes.