Answer:
1. [H+] = 1 x 10^-4mol/L
2. [OH-] = 1 x 10^-10mol/L
Explanation:
1. From the question given, the pH is 4.0. We can obtain the value of the value of the hydrogen ion concentration [H+] as follows:
pH = —Log[H+]
4 = —Log[H+]
—4 = Log[H+]
Anti-log of —4
[H+] = 1 x 10^-4mol/L
2. Recall: [H+] x [OH-] = 1 x 10^-14
But [H+] = 1 x 10^-4mol/L
1 x 10^-4 x [OH-] = 1 x 10^-14
Divide both side by 1 x 10^-4mol/L
[OH-] = 1 x 10^-14/1 x 10^-4
[OH-] = 1 x 10^-10mol/L
Answer:
MoO₃
Explanation:
To solve this question we must find the moles of molybdenum in Mo2O3. The moles of Mo remain constant in the new oxide. With the differences in masses we can find the mass of oxygen and its moles obtaining the empirical formula as follows:
<em>Moles Mo2O3 -Molar mass: 239,878g/mol-</em>
11.79g * (1mol / 239.878g) = 0.04915 moles Mo2O3 * (2mol Mo / 1mol Mo2O3) = 0.09830 moles Mo
<em>Mass Mo in the oxides:</em>
0.09830 moles Mo * (95.95g/mol) = 9.432g Mo
<em>Mass oxygen in the new oxide:</em>
14.151g - 9.432g = 4.719g oxygen
<em>Moles Oxygen:</em>
4.719g oxygen * (1mol/16g) = 0.2949 moles O
The ratio of moles of O/Mo:
0.2949molO / 0.09830mol Mo = 3
That means there are 3 moles of oxygen per mole of Molybdenum and the empirical formula is:
<h3>MoO₃</h3>
Answer:
C. Chemical Energy
Explanation:
The energy that stored in the substance or in compounds is called chemical energy which released when the substance reacts.
A substance is made up of atoms and molecules and chemical energy is present in those atoms or molecules. When a chemical reaction takes place, these energy released from atoms and molecules.
Chemical energy can be released in the form of thermal energy (heat) and mechanical energy (working ability).
Hence, the correct answer is "C. Chemical Energy".
If you were to take water (like many other materials) and break it up into almost the smallest things you could, you’d get molecules. If the molecules are stuck together really tightly in a regular pattern, then they’re called a solid. The solid form of water is ice. This actually makes a lot of sense, because it certainly does seem like all the little parts of a solid (like ice) are stuck together very tightly.
When you heat something up, it makes the molecules move faster. If you heat up a typical solid, it melts and becomes a liquid. In a liquid (like water), the molecules are still stuck together, but they can move around some. What actually happens is that the molecules are still sort of sticking together, but they’re constantly breaking apart and sticking to different molecules. This also makes sense when you think about water. Water sort of sticks together, but it breaks apart /really/ easily.
If you heat a liquid like water up even more (like if you put it in a pot on the stove), then the molecules will move around so fast that they can’t even hold on to each other at all. When this happens, all of the molecules go flying apart and become a gas (like when you boil water to make steam). The process of gas molecules leaving the liquid to go into the gas is called "evaporation." The opposite process is called "condensation."
<span>Hope this answers your question!</span>
