Answer:
Accelerated erosion or change in cover tend to persist and grow over time because the continuous erosion of the channel further escalate the rate of erosion by further widening of the channel unless there is a human intervention to stop this. Once the vegetative cover of a soil is altered, it leaves room for erosion (the degree of the erosion depends on the degree of loss or gain of vegetative cover). In a bad case where there is a loss of vegetative covering of the soil, erosion sets in, washing away the top soil and reducing the cover vegetation even more. These two activities are those type of activities that grows over time once they are activated.
Answer:
1. 6.005 g
2. 22.9 mL
3. Until the mixtures becomes homogeneous.
Explanation:
A buffer is a solution where a weak acid is in equilibrium with its conjugate base (its anion) or a weak base is in equilibrium with its conjugate base (its cation). The buffer remains the pH almost unaltered because it shifts the equilibrium if an acid or base is added.
1. The pH of a buffer can be calculated by the Henderson-Hasselbalch equation:
pH = pKa + log[A⁻]/[HA]
Where [A⁻] is the concentration of the conjugate base (the anion) of the acid, and HA is the acid concentration.
5.10 = 4.76 + log[A⁻]/[HA]
log[A⁻]/[HA] = 5.10 - 4.76
log[A⁻]/[HA] = 0.34
[A⁻]/[HA] = 
[A⁻]/[HA] = 2.1878
Because the volume is the same, we can replace the concentration by the number of moles (n):
nA⁻/nHA = 2.1878
nA⁻ = 2.1878*nHA
The total number of moles of the substances in the buffer is: 0.200 mol/L * 0.5 L = 0.1 mol
nA⁻ + nHA = 0.1
2.1878*nHA + n HA = 0.1
3.1878nHA = 0.1
nHA = 0.0314 mol
nA⁻ = 0.0686 mol
The total number of moles of acetic acid needed is 0.1 mol (both substances may be from it):
m = MW*mol
m = 60.05*0.1 = 6.005 g
2. NaOH must react with acetic acid to form the anion, so for a 1:1 reaction, it will be needed 0.0686 mol of NaOH:
V = mol/concentration
V = 0.0686/3
V = 0.0229 L = 22.9 mL
3. The buffer must be a homogeneous solution, it means that it can't be noticed phases in the buffer, so the flask must be inverted until all the buffer is diluted in water, and it will be noticed when the solution becomes homogenous.
Answer:
D
Explanation:
Elements in the same group (vertical columns) have the same number of valence electrons. These elements behave similarly because they will either give up or take the same number of electrons to fill their valence shell. Since potassium has 1 valence electron, it will most likely give up one electron. Out of all of the answer options, the only element that is in the same group as potassium is francium.
Here is the link to the answer:
Answer:
The radial velocity curve describes how fast a star is moving in its orbit around a center of mass ( m )
Curve amplitude : This is the maximum value of the radial velocity curve
Radial velocity shape ; The shape of Radial velocity curve is parabolic in nature
Orbital period : Orbital period is the time taken by the star to make one complete rotation in its orbit
Explanation:
The radial velocity curve describes how fast a star is moving in its orbit around a center of mass ( m ) while Curve amplitude is the maximum value of the radial velocity curve also The shape of Radial velocity curve is parabolic in nature. and Orbital period is the time taken by the star to make one complete rotation in its orbit
