Five to ten million years ago, the tops of underwater Galapagos volcanoes appeared above water for the first time about 600 km from mainland Ecuador in the middle of the Pacific Ocean. Those volcanic peaks were completely devoid of plant and animal life. All plants and animals that are now native to the islands must have arrived to the islands originally through some form of long-distance dispersal.There are two main ways for species to make their way to remote islands. The first method is by air in the form of flying or being blown by wind, and the second method is by sea while swimming or floating, sometimes with the aid of rafts of tangled vegetation.
Answer:
1. 58.5g/mol
2. 261g/mol
3. 158g/mol
4. 71g/mol
5. 44g/mol
Explanation:
The molar mass of a compound is the total mass of the sum of masses of all individual elements that make up the compound. First, we need to know the atomic masses of each element in a compound.
1. NaCl
Where; Na = 23, and Cl = 35.5
Molar mass of NaCl = 23 + 35.5
= 58.5g/mol
2. Ba(NO3)2:
Where; Ba = 137, N = 14, O = 16
Molar mass of Ba(NO3)2: 137 + {14 + 16(3)} 2
137 + (14 + 48)2
137 + (62)2
137 + 124
= 261g/mol
3. K(MnO4)
Where; K = 39, Mn = 55, O = 16
Molar mass of KMnO4 = 39 + 55 + 16(4)
= 94 + 64
= 158g/mol
4. Cl2
Where; Cl = 35.5
Molar mass of Cl2 = 35.5(2)
= 71g/mol
5. CO2
Where; C = 12, O = 16
Molar Mass of CO2 = 12 + 16(2)
= 12 + 32
= 44g/mol
Answer:
H-F bonds are the strongest.
As Fluorine is the most electronegative element.
Answer:
Explanation:
You should allow the solvent to drop to the level of the adsorvent, so it would never run dry.
When you let your sample to run dry it will never finish to flow from the adsorbent depending of it polarity.
Water should not be used because it can dissolve the adsorbent.
You could use another technique to identify the compound, as an infrared or a ultraviolet detector. You can also, if you know the compounds, identify it for the retention time, for example, if you need to detect two compounds, one more polar than the other, and use a polar adsorbent and a non-polar solvent, the first compound to exit the column will be the less polar one, because it will have a bigger interaction with the solvent than the stationary phase (adsorbent) and will go faster, the second will be the more polar one, because it will have a bigger interaction with the stationary phase.
Answer:
≈ 0.10M
Explanation:
[A]o = 0.27M
Rate constant, k = 0.75 s−1
[A] = ?
time, t = 1.3
Integrated formular for a first order reaction is given as;
ln[A] = ln[A]o − kt
ln[A] = ln(0.27) - 0.75(1.3)
ln[A] = -1.309 - 0.975
ln[A] = -2.284
[A] = 0.1019M ≈ 0.10M
